Clear, concise, easy to understand usable information. No assumptions about a DIY mechanic's knowledge. The benchmark for repair videos. Great job. Please make a video on troubleshooting cooling fans and associated electrical system components on a 2004 VW GTI VR6 2.8L.
first time here.....subscribed immediately. Kudos to the young presenter...very clear and just about right amount of technical for my level of knowledge (liked that pulley comparison with bicycle crank) 👍
Nate, I know this "how to" is 2 yrs old but it is excellent and has helped me. I am the second owner of a Lexus. Lexus has all of the records of what was done to the car prior to me, which was frequent oil changes and detailing. Now that I'm approaching 100K miles, I realize that nothing was done on it but the few things that needed replacing during my ownership.....speed sensor and rear brakes. I do not fix my own cars, but I will definitely buy a multimeter tester because I'm seeing an alternator in my future. Great job! 😎
This is the best site and video I have seen on this red battery light issue, thank you for up the very simple explanation, with clear and concise instructions. Thank you!!!
yep this is Bosch engineers going to town on efficiency to save gasoline. If you have a fancy sensor (Temp, Amp, Volt) on your battery terminal good chance your ECU has "opportunistic charging" feature. Great while it works then hundreds ways to fail 😉
Be aware of your multimeter's cables when working around a running engine. They could become entangled in the drive belt, likely destroying the meter and possibly injuring you.
Yea, I’m surprised He did not Mention a little safety around a running engine for Women especially that might want to try thier hand at auto repair. Take off any jewelry, necklaces etc while working around a running engine.
@@OcRefrigDo you know how many men wear bracelets and rings? Also, men, keep your ponytails away from the running alternator belt. There……I fixed your comment! 🤣
A great video Nate. It is no wonder I like old vehicles - 2x '80's MB. 1/ I always carry a spare belt, but make sure it is the right one. I got caught. On systems with twin belts, eg 380, make sure they are the same actual, not nominal, length. 2/ I start with the battery. If it is not 12.7 volts something is wrong. I then turn on all the lights and re-read it. If the voltage has collapsed the battery is shot. 3/ If the battery is not holding charge check the standing current drain. The drain should be about 10 mAmps. Setting to Amps DC connect one meter end to the positive wire and the other to the positive post. Then, without loosing continuity remove the positive wire from the post. Two people are handy for this manoeuvre. Warning. On a modern car if you loose continuity you may have to reset all the control systems. See Facts Over Feelings92. 4/ If the standing current is fine but the battery is not holding charge look for irregular discharges. My wireless standby capacitor periodically turned into a 4 ohm resistor. Not enough to blow the fuse but enough to flatten an occasional use car. 5/ If the alternator is over 14 volts it has lost battery contact. Either a dirty battery post or the control unit is faulty.
@@twerktospec No, no, no! New-age electrons are skinny weaklings compared to the ones 50 years ago. There are so many more of them these days and food is shorted. 🙂.
Really enjoyed the video! Congratulations on such a thorough and informative rundown of such a common problem. I would like to ask you if the old myth of pulling the positive off the battery, while the vehicle is on, and the vehicle turns off, does it mean the alternator is bad? Appreciate your feedback. Thanks again. Dodge caravan RT 2016.
The same is my question-if I remove the positive from my battery while engine is on , the engine stops after few seconds Does it mean my alternator is faulty ???
To your point: Well said! If your alternator is buried, then this doesn’t really apply. I love how people try to make things sound so simple and quick/easy. My wife’s Q5 alternator--childbirth is probably easier than removing the alternator in this car. Or testing it. 🤣😂🤣😂.
I have a Dodge nitro 2.8 I live in the UK England, my problem is that the battery light came on and I had to drive 20 miles on my return journey. The Dodge came to us not after the power supply died. I get a jumpstart or another vehicle to Home that evening with the lights which was about half a mile. , I think that you diagnosis and health towards finding the fault with my vehicle is that the alternator on the Dodge 2.8 is at fault, Charged the battery or in the process of charging to see if the car start on the battery and then I will do the test that shown video this is a great helping her as a tutoring video and I thank you for your help. Have a great day..🇬🇧🤝🇺🇸🇬🇧👌
Just like all of your videos, this is also very informative and an awesome video, Thank you so much FCP EURO, for your great videos and contents, keep up this awesome work and please upload more videos. As I'm an automotive technician, these videos are supremely useful for me. Thank you so much FCP EURO.!
Very insightful video on charging system, covers checks on battery, alternator, obd scanner, explain alternator how it works even a DIY person can understand 👌🏻
I needed a few jumpstarts over the past few weeks, I was told the blower and the resistor for my Q5 need to be replaced, my battery is good, the diagnosis recommended humidity sensor too, are all these working together to cool the car? I'm more concerned about the car not wanting to start now than the AC blowing hot air. So, I'm thinking of maybe replacing the alternator first. I will very much appreciate any opinions you may have on that. Thanks much for your informative video!
Learnt a lot thank you ! My car was charging - but on a long journey stops charging on the way back! - everything is new - i am completely stumped - new connectors new wires , now wont charge at all! Focus mk1
1999 ford taurus se. We had similar issues u explained in the video, After replacing alternator and battery..Battery light won't go out. after couple months. car died. dash lights, gauges, blinker lights, stereo. and battery wont charge. check megafuse before looking in the alternator?? your video very good.
Wow... I'm so glad I watched this video because I almost didn't! Lol. I learned quite a few things here and I'm really impressed!!! Excellent video, very well made and Nate did an awesome job with it!!! Again...wow!!! Thank you!!! : ) Don W., Ohio, USA
Great video; did you do a video when the alternator was actually changed? This is fascinating. Learning all the time. Regardless of lockdown. Thank you.
Clear , yet somewhat high pace for a not exactly knowledgeable 67 year old. the vid , amongst other things, convinced me to get an affordable multimeter :)
If the battery is failing then use a manual load tester on the battery. If no load tester is available then use a multi-meter and look for a reading for around 12.2 ~ 12.3 volts with the car off. With the car running the readings will be around 14.0 ~ 14.4 volts. You can use a 12 volt cigarette socket voltage output tester as well as they are cheap and work really really well. If you are really careful you can disconnect the battery while the car is running. If the car dies when the battery is disconnected then the problem is with alternator. The 14.0 volts ~14.4 volts indicates that the alternator is working properly. You can always boost the car to get it running and then drive it around for 20 minutes. If you try to start the car again and you get nothing, the problem is the battery as the battery should be charged enough to restart the car at this point.
You forgot a very important part of the charging system. Same problem as this AFTER replacing BOTH alt and battery. Replacing the starter cured the problem. Hot wire from battery and alt both go to the starter solenoid. Bad solenoid can burn the hot wires going to alt and battery.
Great video... My car just died on me today while it was running... can this be anything other than the alternator? I have charged it and it starts right up again as usual and the problem repeats itself after driving a long distance.. I get a red battery icon with no message. Also i've been noticing a very bumpy/rough idle lately would a bad alternator cause this? It felt like vehicle misfire but no rpm fluctuation occurred. Lastly I see a code that says there is an issue communicating with the starter or alternator "1337". Is it just time for a new alternator?
Very helpful and useful video, thank you! Would a faulty alternator fuse also be able to stop the alternator charging the battery? I have a 2006 2.5 Toyota Hilux with a new battery that runs the vehicle for a day or two if the battery is charged up but then it starts to fade, the lights fade, battery light goes on and a while later the vehicle 'dies' as though being turned off
Hi - Great Vid! - We need you more guys like you on you tube! ......I've got a 2016 330e petrol phev (F30) and recently got this Battery warning message come up intermittantly, especially when i start the car with no charge to the electric battery and run from petrol. When i go to 'save option' to build some charge to the battery, the warning message comes up and then disappears allowing me to charge - but the error re-appears stopping the charge and then goes away and then allows me to charge again. Could this be the alternator? In addition - Ive recently had it recalled for the starter motor from BMW UK - Could this be anything to do with it?
Too much mis-information here, so will just mention a couple of items: - The GOOD: info about free wheeling clutch in pulley; some might overlook that when troubleshooting - The BAD: You don't even mention the most important part - the alternator brushes! For symptoms like this, 99 times out of 100, the brushes have simply worn out! And where are the brushes? Incorporated into the "voltage regulator" which is serviceable item, generally cost around $60 or so. Less common, but possible, is one of the diodes in the diode pack has failed (either shorted or opened). You won't catch this issue using the diagnostics applied in this video. You either have to remove the diode pack from the alternator and test each diode (generally there are six) with an ohm meter, or you can diagnose on a running car with an o-scope. The bearings almost never fail. And the windings almost never ever ever fail! Yet at 12:20 of the video, you declare that is the problem here. - SUMMARY: All moot points anyway since most DIYers and professional techs alike will simply replace the alternator with a rebuild. Which is a shame since, as I mentioned above, 99% of the time, new brushes is all you need. Again, new brushes are included in a new voltage regulator assembly. Unfortunately it has become very difficult for a DIYer to source just the brushes. I've been working on cars for over 50 years and never seen any other alternator failure modes than what I mentioned above. One caveat; the slip rings (which the brushes ride on and contact when alternator is rotating) will wear out eventually, but this is typically 200K to 300K miles range. FYI
Here Here (hear hear?) I apologize for not reading down to here before commenting. My son bought the brushes alone for $0.50 about 2 years ago, and it took him 15 minutes to replace them. Good kid.
Hi!Any ideas.Alternator and battery replaced serpentine belt replaced.The reason for replacement was serpentine belt was shredded and burnt on pulleys.Pulkeys cleaned.Clutch changed 60-70 miles before belt burnt pn pulleys.Timing belt done 2000 miles ago.Garage said the alternator pulkey disenged causing belt to shredd.but still battery light comes on.It won't come on if car has sat overnight.Take it for drive ,switch engine off try to start it after 10 minutes light is on.Sometimes not.It is Dodge caliber 2.0 diesel engine 2007.reg European variant.
Another common failure point is the brushes. They wear out over time (get too short to make good contact) or when they get wet. The tell-tale is that the alternator idiot light comes on or flickers at idle and goes out when you rev it up. They are cheap and usually fairly easy to replace. Sometimes they are attached to the regulator or need soldering to replace. Again fairly easy considering the price of an alternator.
Dear FCP. Please make an addendum to your video with instruction to DIY not to disconect(or connect) the battery terminals on a running car as some of the comments below were suggesting.
Great info. I’ve today had a new alternator fitted however I doubt the mechanic actually tested the original alternator. Cost $1100 dollars. The vehicle has 47000klms. And services by time rather than klms. I’ll check out your recommendations. Regards
Very informative. However...most shops will not repair an alternator. They'll want to replace it entirely. It requires less time and labor costs. When the alternator on my 2005 Volvo X90 V8 malfunctioned, I replaced it with a Bosch remanufactured alternator for about $180.00 after the core charge reimbursement. Took me about about an hour to replace it myself. Didn't have to spend time trying to source the alternator parts, rebuilding it and reinstalling the alternator. Just buy another alternator.
Very nice video; Thank you. My xtool has an additional variable it reports on the alternator, % loading which ranges from 72% - 99%. When idling, it read 89%. What is the relavance of % loading.
Hi there My car iwas charging 13.7v at idle. i Changed the battery and still it charges 13.7v at idle i Think it should be between 14 and 14.2v at idle , not sure. Do you think it might be the regulator?...Thank's for the video👍
Great video, so my issue is that when my car is off the voltage is perfect but when i start engine and on all the functions such as lights, stereo, wipers the voltage goes to around 15.5, is there something wrong with my alternator and do you think it could be repaired by replacing the voltage regulator, any response would be greatly appreciated, car is jaguar xf 2013
Really good video. But, did you know that you can see your alternator voltage, in real time, while driving, by installing an OBDII plug and loading the TorquePro ap?
Hi I have a nightmare going on with my 07 Honda CRV. OK I had my alternator replaced with a high output model sourced from a reputable alternator manufacture in Tucson, Arizona. When having the alternator installed, I recall the gentleman doing it stating that he needed a smaller belt because the pulley was smaller than the stock model. The alternator I purchased was designed specifically for the make and model gentleman installing it had me go to O’Reillys to purchase a different belt which was unavailable that only one size made for this car he said he adjusted the tensioner on the belt and said it was fine . The vehicle ran fine. Everything was good until I had a can of clearcoat that blew up in the driver side cabinet underneath the steering wheel. I had the vehicle, detailed, and what I could tell, cleaned to the best of their ability which I little find out they used a power washer to spray most of the stuff off under my steering wheel , it wouldn’t start at first and I let her drive for about an hour. The vehicle started. I went home and the following day I couldn’t get my vehicle to start and there’s a flashing green key on the dashboard at that point. I thought it could be my key fob, because on top of the spray tan blowing up, my key fob broke in the middle key came out of the fob self Which worked by holding the follow-up to the ignition for a couple times and then stopped completely. I went to arrowhead Honda dealership and purchased a new cut key to have a number and put the internals from the broken five into the new fob. got home and the vehicle and I start, I had on the come out to my vehicle in my house with a new key new internals and had a program to the vehicle which was successful but the green light continued flashing and when I start after a few different Lock Smith‘s coming to the house one of them gave me a code that Red immobilizer is not communicating with the IMOS. They told me to replace the multiplex control unit Which was sprayed on the steering wheel because it’s located on the fuse box in the driver side cabin last night I replace that multiplex control unit and it is in the vehicle and about to have Locksmith come out to program the keys and see if this works. It cost me $100 to have a key programmed and if that multiplex control unit is not it then I will have to go from there. I hope you can kind of understand my confusion and there’s different things that could be wrong and it could possibly be the alternator pulley not doing his job correctly as well. After watching this I believe that could be an option. If you could please contact me and give me a little bit of advice and what you recommend me doing. I’m at a complete and total loss. Thank you so much.
Hey thanks for this, just a question what happens when battery light and power steering lights comes on, i had experienced this lately and i could hear a hissing sound coming from the alternator ends. Hadn't checked the voltage of the battery yet but do you think one reason for the alternator failing also was due to the engine mounts or vigorous movements around the alternator.
Great video but before using the VOM meter on volts I would put the meter on ohms and test the continuity of the test leads. THEN make sure you put the dial on the meter to volts before you test the battery voltage. FCP great company I buy all my Mercedes parts there.
I have a cigarette lighter usb with volt It shows when car running the voltage goes to 14 when not running it shows 12.2 so point is u can just buy 5 bucks usb with colt display and plug it into your cigarette lighter it will show voltage before and during engine run. Good explanation on how to fix
So if there is corrosion on the battery terminals the battery won't be charging and you may mistakenly blame the alternator and spend unnecessary money replacing it. Am I right? Also if there is corrosion on the battery terminals there will be a larger strain on the alternator and it fail prematurely. So keeping the battery terminals corrosion-free is paramount to keeping the charging system from failing. So make sure to keep the battery terminals well maintained every 6 months - - - - even in a new car.
@@bernardocisneros4402 Well, I was stranded far from home in a parking lot this summer. I thought I had a dead battery. I found someone to help me with a jump with my jumper cables and that didn't work. So I thought I was going to have to get a ride to a store to buy a new battery. Then the guy who was helping me saw some corrosion on the battery terminals and I was able to knock some of it off. After that I was able to start the car. Then I drove home and did a thorough cleaning of the terminals. I also found my positive terminal was no longer making a good connection and could not be tightened down enough to make a good connection so I had to replace it.
Hi. I'd like to ask a question. I have a Volvo v50 t5 2005. I am getting warning lights on the dash, not of a battery but brake failure, unti skid service needed, windshield wipers just working without the stork not been touch, no indicate working. So my mechanic suggested the altinater, but seen videos that it might be cem. Any advice? Please 🙏
Hey Nate, so, my car (Mercedes-Benz C220 CDI w203), its not charging until I hit 2.5k RPM, suddently it goes from 11.5~12.5v to ~14v. May it be a voltage regulator issue or the alternator itself? Thank you.
Nate is a cutie. Just because a battery light comes on - it doesn’t necessary mean the battery is the issue. Especially on newer cars. Could be anything electrical.
Thanks for another great video. Would be good to see a video that helps you test how much life is left in your car battery. I.e. does it need to be changed now or in the near future or is it fine etc
An easy test to do is to measure the voltage on the battery as you are starting the car. If it goes below 10V then you know that it needs to be changed. If it is cold outside then you may want to change it at a slightly higher voltage, like 10,3V. This needs to be done on a battery that has been charged up.
Had battery light and red check engine light on. Faulty alternator as diagnosed by breakdown and garage. Alternator replaced but both battery light and red check engine light still there. Car voltage is over 13.8 when running but the both lights have decided to stay
Simple question. I replaced my battery a week ago. With engine running I see 12V (same as engine stopped). Belt to alternator good and spinning alternator. Today my alternator light goes on. I suspect a bad alternator so I have been charging my battery daily with a 10/2amp Sears charger. Question: Can I drive in the day for less than 1hr? It's been raining so I can't replace the alternator till the weather is dry (no garage).
Nate: I have a 2017 VOLVO xc60 with auto start/stop. I’ve replaced the auxiliary battery twice already. Sometimes the system works and sometimes it doesn’t work. I don’t have an alternator issue or belt issue. I’m curious why my system works sometimes and at other times it doesn’t work. Wires are ok. Belt is ok. Alternator is ok. What could be the issue?
I have a 2010 Nissan Frontier, 6 cylinder. 4.0 engine. The charging voltage fluctuates, it starts at 14.1 on start up, and with in 3 minutes charging rate always starts dropping down eventually to as low as 12.7, then usually goes back to 12.8 or 12.9, then will hang around 13.0 to 13.1 volts. When I turn on the AC, and/or radio, and/or lights. It drops to 12.8 volts. Then it may or may not go back to 13.0 or 13.1. Mechanic said it was the alternator and put in a brand new alternator. It acts the same way. Went to another mechanic he supposedly did a diagnostics and said the alternator is doing its job, but the battery tested only at 44 percent. He put in a premium battery and the battery is now holding a full charge for the last 3 days. Although, the way the charging system seems to be somewhat sufficient; to me there seems to be to be something wrong in the charging system for all these fluctuations, because when AC, etc. charging rate should go up, not down. I m concerned that eventually it will get worse.
I have a 2016 Frontier and I'm a mechanic. You're Frontier is doing exactly what it was designed to do. The only thing you have to do is to keep the top of the battery and the battery terminals clean. Also check the B+ terminal on the alternator to make sure it's clean. By clean, I mean free of grime and corrosion. Never go back to the first mechanic. He doesn't know what he's doing. A good mechanic can tell you in 10 minutes if it's the alternator or battery or both. Our trucks voltage regulation is not controlled by a regulator in the alternator. It's controlled by the engine control module (ECM) and Intelligent Power Distribution Module (IPDM). The second mechanic knows what he's doing. If you don't have a mechanic, keep going to him. One thing I will recommend is to use a flooded lead acid battery. These are the old school type of batteries that have a liquid electrolyte. Do not use an AGM. The charging system in our trucks is not designed for an AGM battery. Our charging system, charges at too low of a voltage most of the time for an AGM. An AGM needs 13.8 to 14.6 Volts at all times or else it will fail to charge properly and die prematurely. The reason why the system voltage goes down on your truck when you turn on the air conditioning is because the A/C is pulling more amps (current), so the voltage goes down. To show you this is what's going on, put a voltmeter on the battery and make note of the voltage. While looking at the voltmeter, have someone start the truck, and you will see the voltage drop while the starter is turning. That's because the starter is pulling a lot of amps to turn the engine to get it started. If you have the min/max function on your multimeter, use it and you will see how low the voltage goes. The A/C does the same thing to the alternator when you turn it on. The voltage drops but the current (amps) goes up. Put an amp clamp on the thick wire that goes from the alternator to the battery and you will see this. Just make sure you keep the top of the battery, it's terminals, and anything connected to it's terminals clean.
I did take it to the dealer and he confirmed that as you say this is how this system works. I know that the voltage goes down when on start up or turning on AC . When I turn on the AC or on start my old 2006 Honda Accord four-cylinder, of course the charging rate down, then goes right back up to 14.2 charging rate almost immediately afterwards and keeps a steady 14.2 charging rate. Of course, also upon startup, it acts the same way. Also, my friend’s old 2004 Chevy, same thing he starts it up, turn the on l AC, voltage drops and then the charging rate goes right back up. Naturally the voltage drops and then the meter goes back into the original charging range. Obviously, these old vehicles don’t have ECM’s. It just seemed odd it doesn’t work this way on the Frontier. I certainly appreciate your information. I feel better that the dealer also confirmed what you say as far as the system working the way it does. The mechanic did put an AGM battery in the 2010 Frontier at my request due my thinking that is the better battery and an improvement over the old type, but I guess for this application it’s not the best choice according to you. He didn’t seem aware of that. Also, he made me skeptical of him, even though he was correct, because he really didn’t seem sure of himself and even asked me if I checked with the dealer to see if there was a bulletin out this being a problem.
@@mannymanano Every AGM battery has a label on it warning you about the 13.8V to 14.6V voltage requirements. I bought one at O'reillys and it only lasted a little less than 3 years. I bought it before I knew about the voltage requirement. The regular flooded lead acid AC Delco lasts me a little over 5 years.
Hello i have BMW 730d 2008 and when i start the car it says Alternator fault and some times indicators left or right failure but for short time like seconds ??????!
I have an issue where I would start the car and the battery light would stay on. I then turn it on and off 3-4 times then on the 5th try, the battery light goes away. I then drive for 10 minutes without the light on dash. I then park somewhere turn it off. Once I turn it back on the light comes on again.
Question my BMW battery dies if I don’t drive it every day. 1 day starts like it should but if I wait 2 days the battery is dead. Have replaced the battery twice. How do I check to see if the alternator is still producing or drawing amps with the car off ?
You can do the same test Nate does around the 5-minute mark to verify if your alternator is charging the battery while running. 13.8-14.8 volts is an acceptable range for a healthy charging system.
Please help, my car charging lamp blinks on an off while running. Battery is not charging. When a new alternator is add it becomes ok for few days an the same problem comes again, please help
Clear, concise, easy to understand usable information. No assumptions about a DIY mechanic's knowledge. The benchmark for repair videos. Great job. Please make a video on troubleshooting cooling fans and associated electrical system components on a 2004 VW GTI VR6 2.8L.
11o
Nmn
first time here.....subscribed immediately. Kudos to the young presenter...very clear and just about right amount of technical for my level of knowledge (liked that pulley comparison with bicycle crank) 👍
One of the best, best best video to understand without moving the camera where it goes everywhere. Thank you
This was perfect 👍 A++
Nate, I know this "how to" is 2 yrs old but it is excellent and has helped me. I am the second owner of a Lexus. Lexus has all of the records of what was done to the car prior to me, which was frequent oil changes and detailing. Now that I'm approaching 100K miles, I realize that nothing was done on it but the few things that needed replacing during my ownership.....speed sensor and rear brakes. I do not fix my own cars, but I will definitely buy a multimeter tester because I'm seeing an alternator in my future. Great job! 😎
For a guy man you know your stuff,glad that I came across this channel. Thank you for sharing your knowledge and expertise
How you know he's gey 🏳️🌈???
This is the best site and video I have seen on this red battery light issue, thank you for up the very simple explanation, with clear and concise instructions. Thank you!!!
I had no idea alternators could adjust voltage depending on demand. Must be why these things are so expensive.
Thank you for the in-depth article!
yep this is Bosch engineers going to town on efficiency to save gasoline. If you have a fancy sensor (Temp, Amp, Volt) on your battery terminal good chance your ECU has "opportunistic charging" feature.
Great while it works then hundreds ways to fail 😉
@@glasser2819 Things are constantly evolving ^.^
You and your team did an excellent job on this video. Thank you, it's been very helpful.
Thank you for watching David!
What a great video - perfectly written and delivered. Glad to know all the business I do with FCP supports stuff like this - Thanks!!
Be aware of your multimeter's cables when working around a running engine. They could become entangled in the drive belt, likely destroying the meter and possibly injuring you.
@@borick8744 XD
First-hand experience? OUCH.
Yea, I’m surprised He did not Mention a little safety around a running engine for Women especially that might want to try thier hand at auto repair. Take off any jewelry, necklaces etc while working around a running engine.
@@OcRefrigdont be a 🤡, he can’t teach common sense
@@OcRefrigDo you know how many men wear bracelets and rings? Also, men, keep your ponytails away from the running alternator belt. There……I fixed your comment! 🤣
Great video i must say and extremely well put forward, you should be on television as a speaker well done young man
A great video Nate. It is no wonder I like old vehicles - 2x '80's MB.
1/ I always carry a spare belt, but make sure it is the right one. I got caught.
On systems with twin belts, eg 380, make sure they are the same actual, not nominal, length.
2/ I start with the battery. If it is not 12.7 volts something is wrong. I then turn on all the lights and re-read it. If the voltage has collapsed the battery is shot.
3/ If the battery is not holding charge check the standing current drain. The drain should be about 10 mAmps.
Setting to Amps DC connect one meter end to the positive wire and the other to the positive post. Then, without loosing continuity remove the positive wire from the post. Two people are handy for this manoeuvre.
Warning. On a modern car if you loose continuity you may have to reset all the control systems. See Facts Over Feelings92.
4/ If the standing current is fine but the battery is not holding charge look for irregular discharges. My wireless standby capacitor periodically turned into a 4 ohm resistor. Not enough to blow the fuse but enough to flatten an occasional use car.
5/ If the alternator is over 14 volts it has lost battery contact. Either a dirty battery post or the control unit is faulty.
Or you could just live in the current world
@@twerktospec No, no, no! New-age electrons are skinny weaklings compared to the ones 50 years ago. There are so many more of them these days and food is shorted. 🙂.
Thanks Bern. I didn’t know that. I certainly appreciate you getting back to me. I appreciate any help. Thanks again.
FANTASTIC PRESENTATION OF TOPIC WITH BERY EASY WAY TO DIGEST. GOOD WORK
Thank you for the in depth lesson. Was great, and thanks for making these amazing videos for DIY
Glad you like them, and found it helpful!
Really enjoyed the video! Congratulations on such a thorough and informative rundown of such a common problem. I would like to ask you if the old myth of pulling the positive off the battery, while the vehicle is on, and the vehicle turns off, does it mean the alternator is bad? Appreciate your feedback. Thanks again.
Dodge caravan RT 2016.
Yes
The same is my question-if I remove the positive from my battery while engine is on , the engine stops after few seconds
Does it mean my alternator is faulty ???
Yes. The red of ,car dies, alt is in need of help
One of the best, most informative videos I've seen. Well-done. Too bad my alternator is so buried, it's almost inaccessible.
To your point:
Well said! If your alternator is buried, then this doesn’t really apply. I love how people try to make things sound so simple and quick/easy. My wife’s Q5 alternator--childbirth is probably easier than removing the alternator in this car. Or testing it. 🤣😂🤣😂.
I have a Dodge nitro 2.8 I live in the UK England, my problem is that the battery light came on and I had to drive 20 miles on my return journey. The Dodge came to us not after the power supply died. I get a jumpstart or another vehicle to Home that evening with the lights which was about half a mile. , I think that you diagnosis and health towards finding the fault with my vehicle is that the alternator on the Dodge 2.8 is at fault, Charged the battery or in the process of charging to see if the car start on the battery and then I will do the test that shown video this is a great helping her as a tutoring video and I thank you for your help. Have a great day..🇬🇧🤝🇺🇸🇬🇧👌
Just like all of your videos, this is also very informative and an awesome video,
Thank you so much FCP EURO, for your great videos and contents, keep up this awesome work and please upload more videos.
As I'm an automotive technician, these videos are supremely useful for me.
Thank you so much FCP EURO.!
You are very welcome Muhammadreza Sadeqi , glad you enjoy the content we've been producing!
@@fcpeuro Thank you so much.!
Very insightful video on charging system, covers checks on battery, alternator, obd scanner, explain alternator how it works even a DIY person can understand 👌🏻
Thank you for showing where the multimeter dial and leads go to on the multimeter, awesome, a lot leave that bit out.
Good video ! You covered a Failing alternator well but I missed how to diagnose a failing battery 🔋.
With a multimeter readout, if it is less than 12.6 , chances are it is failing
He literally explained it in the video after he did the multimeter test. You failed to watch the video.
I needed a few jumpstarts over the past few weeks, I was told the blower and the resistor for my Q5 need to be replaced, my battery is good, the diagnosis recommended humidity sensor too, are all these working together to cool the car? I'm more concerned about the car not wanting to start now than the AC blowing hot air. So, I'm thinking of maybe replacing the alternator first. I will very much appreciate any opinions you may have on that. Thanks much for your informative video!
Learnt a lot thank you ! My car was charging - but on a long journey stops charging on the way back! - everything is new - i am completely stumped - new connectors new wires , now wont charge at all! Focus mk1
1999 ford taurus se. We had similar issues u explained in the video, After replacing alternator and battery..Battery light won't go out. after couple months. car died. dash lights, gauges, blinker lights, stereo. and battery wont charge. check megafuse before looking in the alternator?? your video very good.
Wow... I'm so glad I watched this video because I almost didn't! Lol. I learned quite a few things here and I'm really impressed!!! Excellent video, very well made and Nate did an awesome job with it!!! Again...wow!!! Thank you!!! : ) Don W., Ohio, USA
Thanks for checking in, Don!
You're welcome, n thanks again for the video!!! 🙂👍
Could it also be a loose wire connecting the alternator and battery?
Is it worth checking the voltage AT the alternator instead of the battery?
Great video; did you do a video when the alternator was actually changed? This is fascinating. Learning all the time. Regardless of lockdown. Thank you.
Hello Jason, Here is the video of the alternator being replaced on this exact Volvo C30. ua-cam.com/video/MGA7eSOtPqI/v-deo.html
Quick and simple. Keep it that way. Many thanks.
A very nice and easy to follow tutorial.
looking forward to get more of such videos.
Thank you so much
Thanks for the love!
Clear , yet somewhat high pace for a not exactly knowledgeable 67 year old. the vid , amongst other things, convinced me to get an affordable multimeter :)
Multimeters are cheap, powerful, versatile
If the battery is failing then use a manual load tester on the battery. If no load tester is available then use a multi-meter and look for a reading for around 12.2 ~ 12.3 volts with the car off. With the car running the readings will be around 14.0 ~ 14.4 volts. You can use a 12 volt cigarette socket voltage output tester as well as they are cheap and work really really well. If you are really careful you can disconnect the battery while the car is running. If the car dies when the battery is disconnected then the problem is with alternator. The 14.0 volts ~14.4 volts indicates that the alternator is working properly. You can always boost the car to get it running and then drive it around for 20 minutes. If you try to start the car again and you get nothing, the problem is the battery as the battery should be charged enough to restart the car at this point.
Great stuff. Just learned a whole bunch. Thanks!
Thanks well Explained , best and most informative videos .
Which autel obd scanner would yall suggest? I have an 09 bmw 328i
You forgot a very important part of the charging system. Same problem as this AFTER replacing BOTH alt and battery. Replacing the starter cured the problem. Hot wire from battery and alt both go to the starter solenoid. Bad solenoid can burn the hot wires going to alt and battery.
Facts something happened to my nissan changed my battery and put 3 alternators
Thank you so much! Hoping to figure out my charging problem on my W124 with this knowledge
Very informative. Outstanding explanation.
Fantastic and thorough video! Thank you.
Great video... My car just died on me today while it was running... can this be anything other than the alternator? I have charged it and it starts right up again as usual and the problem repeats itself after driving a long distance.. I get a red battery icon with no message. Also i've been noticing a very bumpy/rough idle lately would a bad alternator cause this? It felt like vehicle misfire but no rpm fluctuation occurred. Lastly I see a code that says there is an issue communicating with the starter or alternator "1337". Is it just time for a new alternator?
What was your issue?..was it the alternator?
@@IceESole yes
@@Dnasty1 thank you for responding, the same thing happened to me and im not a car person so that helps!
beware of the alternators controlled by the ECU based on feedback from the battery sensor.
Why
Very helpful and useful video, thank you! Would a faulty alternator fuse also be able to stop the alternator charging the battery? I have a 2006 2.5 Toyota Hilux with a new battery that runs the vehicle for a day or two if the battery is charged up but then it starts to fade, the lights fade, battery light goes on and a while later the vehicle 'dies' as though being turned off
Hi - Great Vid! - We need you more guys like you on you tube! ......I've got a 2016 330e petrol phev (F30) and recently got this Battery warning message come up intermittantly, especially when i start the car with no charge to the electric battery and run from petrol. When i go to 'save option' to build some charge to the battery, the warning message comes up and then disappears allowing me to charge - but the error re-appears stopping the charge and then goes away and then allows me to charge again. Could this be the alternator? In addition - Ive recently had it recalled for the starter motor from BMW UK - Could this be anything to do with it?
Thanks so much! Great video so very helpful. Love the visuals!
You are correct with the brands you are referring 😂
They are the only one to generate this problem!
Too much mis-information here, so will just mention a couple of items:
- The GOOD: info about free wheeling clutch in pulley; some might overlook that when troubleshooting
- The BAD: You don't even mention the most important part - the alternator brushes! For symptoms like this, 99 times out of 100, the brushes have simply worn out! And where are the brushes? Incorporated into the "voltage regulator" which is serviceable item, generally cost around $60 or so.
Less common, but possible, is one of the diodes in the diode pack has failed (either shorted or opened). You won't catch this issue using the diagnostics applied in this video. You either have to remove the diode pack from the alternator and test each diode (generally there are six) with an ohm meter, or you can diagnose on a running car with an o-scope. The bearings almost never fail. And the windings almost never ever ever fail! Yet at 12:20 of the video, you declare that is the problem here.
- SUMMARY: All moot points anyway since most DIYers and professional techs alike will simply replace the alternator with a rebuild. Which is a shame since, as I mentioned above, 99% of the time, new brushes is all you need. Again, new brushes are included in a new voltage regulator assembly. Unfortunately it has become very difficult for a DIYer to source just the brushes. I've been working on cars for over 50 years and never seen any other alternator failure modes than what I mentioned above. One caveat; the slip rings (which the brushes ride on and contact when alternator is rotating) will wear out eventually, but this is typically 200K to 300K miles range. FYI
Here Here (hear hear?)
I apologize for not reading down to here before commenting.
My son bought the brushes alone for $0.50 about 2 years ago, and it took him 15 minutes to replace them. Good kid.
Hi!Any ideas.Alternator and battery replaced serpentine belt replaced.The reason for replacement was serpentine belt was shredded and burnt on pulleys.Pulkeys cleaned.Clutch changed 60-70 miles before belt burnt pn pulleys.Timing belt done 2000 miles ago.Garage said the alternator pulkey disenged causing belt to shredd.but still battery light comes on.It won't come on if car has sat overnight.Take it for drive ,switch engine off try to start it after 10 minutes light is on.Sometimes not.It is Dodge caliber 2.0 diesel engine 2007.reg European variant.
Another common failure point is the brushes. They wear out over time (get too short to make good contact) or when they get wet.
The tell-tale is that the alternator idiot light comes on or flickers at idle and goes out when you rev it up.
They are cheap and usually fairly easy to replace.
Sometimes they are attached to the regulator or need soldering to replace. Again fairly easy considering the price of an alternator.
Dear FCP. Please make an addendum to your video with instruction to DIY not to disconect(or connect) the battery terminals on a running car as some of the comments below were suggesting.
Great info. I’ve today had a new alternator fitted however I doubt the mechanic actually tested the original alternator. Cost $1100 dollars. The vehicle has 47000klms. And services by time rather than klms. I’ll check out your recommendations. Regards
Simple explanation, very clear 👍
Great video!! Thank you for the info!
Thanks I appreciate your input on drive belts.
Very informative. However...most shops will not repair an alternator. They'll want to replace it entirely. It requires less time and labor costs. When the alternator on my 2005 Volvo X90 V8 malfunctioned, I replaced it with a Bosch remanufactured alternator for about $180.00 after the core charge reimbursement. Took me about about an hour to replace it myself. Didn't have to spend time trying to source the alternator parts, rebuilding it and reinstalling the alternator. Just buy another alternator.
you can replace the $15 "regulator&brush set" in place under 10mn without removing alternator.
@@glasser2819 Its definitely a case by case basis, whats the most practical and affordable method to fix an alternator issue!
Thanks for the tip 👍👍👍👍👍👍👍👍
Very nice video; Thank you. My xtool has an additional variable it reports on the alternator, % loading which ranges from 72% - 99%. When idling, it read 89%. What is the relavance of % loading.
Brilliant presentation
Hi there
My car iwas charging 13.7v at idle. i Changed the battery and still it charges 13.7v at idle
i Think it should be between 14 and 14.2v at idle , not sure. Do you think it might be the regulator?...Thank's for the video👍
Great explanation, thank you!
Most helpful video found!
Good plain-language demo. Thanks
Great video, so my issue is that when my car is off the voltage is perfect but when i start engine and on all the functions such as lights, stereo, wipers the voltage goes to around 15.5, is there something wrong with my alternator and do you think it could be repaired by replacing the voltage regulator, any response would be greatly appreciated, car is jaguar xf 2013
Really good video. But, did you know that you can see your alternator voltage, in real time, while driving, by installing an OBDII plug and loading the TorquePro ap?
@@412Walk doing all what?
Decent scanners also have live display
@@reallyhappenings5597 True, but having various displays on my phone (which is mounted on my dash) is very helpful.
Most excellent video
Hi I have a nightmare going on with my 07 Honda CRV.
OK I had my alternator replaced with a high output model sourced from a reputable alternator manufacture in Tucson, Arizona.
When having the alternator installed, I recall the gentleman doing it stating that he needed a smaller belt because the pulley was smaller than the stock model. The alternator I purchased was designed specifically for the make and model gentleman installing it had me go to O’Reillys to purchase a different belt which was unavailable that only one size made for this car he said he adjusted the tensioner on the belt and said it was fine .
The vehicle ran fine. Everything was good until I had a can of clearcoat that blew up in the driver side cabinet underneath the steering wheel. I had the vehicle, detailed, and what I could tell, cleaned to the best of their ability which I little find out they used a power washer to spray most of the stuff off under my steering wheel , it wouldn’t start at first and I let her drive for about an hour. The vehicle started. I went home and the following day I couldn’t get my vehicle to start and there’s a flashing green key on the dashboard at that point. I thought it could be my key fob, because on top of the spray tan blowing up, my key fob broke in the middle key came out of the fob self Which worked by holding the follow-up to the ignition for a couple times and then stopped completely. I went to arrowhead Honda dealership and purchased a new cut key to have a number and put the internals from the broken five into the new fob. got home and the vehicle and I start, I had on the come out to my vehicle in my house with a new key new internals and had a program to the vehicle which was successful but the green light continued flashing and when I start after a few different Lock Smith‘s coming to the house one of them gave me a code that Red immobilizer is not communicating with the IMOS. They told me to replace the multiplex control unit Which was sprayed on the steering wheel because it’s located on the fuse box in the driver side cabin last night I replace that multiplex control unit and it is in the vehicle and about to have Locksmith come out to program the keys and see if this works. It cost me $100 to have a key programmed and if that multiplex control unit is not it then I will have to go from there. I hope you can kind of understand my confusion and there’s different things that could be wrong and it could possibly be the alternator pulley not doing his job correctly as well. After watching this I believe that could be an option. If you could please contact me and give me a little bit of advice and what you recommend me doing. I’m at a complete and total loss. Thank you so much.
Hey thanks for this, just a question what happens when battery light and power steering lights comes on, i had experienced this lately and i could hear a hissing sound coming from the alternator ends. Hadn't checked the voltage of the battery yet but do you think one reason for the alternator failing also was due to the engine mounts or vigorous movements around the alternator.
Did you ever figure it out?
What was the end result?
Great video but before using the VOM meter on volts I would put the meter on ohms and test the continuity of the test leads. THEN make sure you put the dial on the meter to volts before you test the battery voltage. FCP great company I buy all my Mercedes parts there.
@FCP Euro where can I get one of those t shirts?
Excellent video 👍
LOVE FCP EURO 💪💪💪
BEST EURO CAR CHANNEL PERIODDDDTTT. lol
Best type of comment PERIOD! Thanks Yoppa999
Great video. Learned something today...👍
Appreciate the information on the video
I have a cigarette lighter usb with volt
It shows when car running the voltage goes to 14 when not running it shows 12.2 so point is u can just buy 5 bucks usb with colt display and plug it into your cigarette lighter it will show voltage before and during engine run. Good explanation on how to fix
Do a video on radiators and when they need tobe replaced. Thanks ps good vid on alternators.
Awesome video and explanation
Thanks Kevin glad you liked the video, we hope to do more like this!
Very helpful video! Thanks!
So if there is corrosion on the battery terminals the battery won't be charging and you may mistakenly blame the alternator and spend unnecessary money replacing it. Am I right? Also if there is corrosion on the battery terminals there will be a larger strain on the alternator and it fail prematurely. So keeping the battery terminals corrosion-free is paramount to keeping the charging system from failing. So make sure to keep the battery terminals well maintained every 6 months - - - - even in a new car.
Yep, just clean them of every oil change and you'll extend the life of the alternator and battery. It's amazing how few people know about this.
@@bernardocisneros4402 Well, I was stranded far from home in a parking lot this summer. I thought I had a dead battery. I found someone to help me with a jump with my jumper cables and that didn't work. So I thought I was going to have to get a ride to a store to buy a new battery. Then the guy who was helping me saw some corrosion on the battery terminals and I was able to knock some of it off. After that I was able to start the car. Then I drove home and did a thorough cleaning of the terminals. I also found my positive terminal was no longer making a good connection and could not be tightened down enough to make a good connection so I had to replace it.
Hi. I'd like to ask a question.
I have a Volvo v50 t5 2005.
I am getting warning lights on the dash, not of a battery but brake failure, unti skid service needed, windshield wipers just working without the stork not been touch, no indicate working.
So my mechanic suggested the altinater, but seen videos that it might be cem.
Any advice? Please 🙏
What if the issue is the opposite to what yoy mentioned. When revving the engine the voltage goes up. But when it goes to idle the voltage goes down?
Would a smallish amount of oil was spilt on coil wires would it affect the alternator
maybe
Hey Nate, so, my car (Mercedes-Benz C220 CDI w203), its not charging until I hit 2.5k RPM, suddently it goes from 11.5~12.5v to ~14v. May it be a voltage regulator issue or the alternator itself? Thank you.
Nate is a cutie. Just because a battery light comes on - it doesn’t necessary mean the battery is the issue. Especially on newer cars. Could be anything electrical.
Thanks for another great video.
Would be good to see a video that helps you test how much life is left in your car battery.
I.e. does it need to be changed now or in the near future or is it fine etc
An easy test to do is to measure the voltage on the battery as you are starting the car. If it goes below 10V then you know that it needs to be changed. If it is cold outside then you may want to change it at a slightly higher voltage, like 10,3V. This needs to be done on a battery that has been charged up.
Had battery light and red check engine light on. Faulty alternator as diagnosed by breakdown and garage. Alternator replaced but both battery light and red check engine light still there. Car voltage is over 13.8 when running but the both lights have decided to stay
I would like to see more of these
Thanks very informative 👍 👌
Thank you so much for the information
Simple question. I replaced my battery a week ago. With engine running I see 12V (same as engine stopped). Belt to alternator good and spinning alternator. Today my alternator light goes on. I suspect a bad alternator so I have been charging my battery daily with a 10/2amp Sears charger.
Question: Can I drive in the day for less than 1hr?
It's been raining so I can't replace the alternator till the weather is dry (no garage).
Wow this is great video thanks 👍🏻
I heard a simple test, with engine running remove the positive cable from battery, if the engine Keeps running its a bad battery. Is this a good test?
Excellent quality video
Great video
Nate: I have a 2017 VOLVO xc60 with auto start/stop. I’ve replaced the auxiliary battery twice already. Sometimes the system works and sometimes it doesn’t work. I don’t have an alternator issue or belt issue. I’m curious why my system works sometimes and at other times it doesn’t work. Wires are ok. Belt is ok. Alternator is ok. What could be the issue?
I have a 2010 Nissan Frontier, 6 cylinder. 4.0 engine. The charging voltage fluctuates, it starts at 14.1 on start up, and with in 3 minutes charging rate always starts dropping down eventually to as low as 12.7, then usually goes back to 12.8 or 12.9, then will hang around 13.0 to 13.1 volts. When I turn on the AC, and/or radio, and/or lights. It drops to 12.8 volts. Then it may or may not go back to 13.0 or 13.1. Mechanic said it was the alternator and put in a brand new alternator. It acts the same way.
Went to another mechanic he supposedly did a diagnostics and said the alternator is doing its job, but the battery tested only at 44 percent. He put in a premium battery and the battery is now holding a full charge for the last 3 days. Although, the way the charging system seems to be somewhat sufficient; to me there seems to be to be something wrong in the charging system for all these fluctuations, because when AC, etc. charging rate should go up, not down. I m concerned that eventually it will get worse.
I have a 2016 Frontier and I'm a mechanic. You're Frontier is doing exactly what it was designed to do. The only thing you have to do is to keep the top of the battery and the battery terminals clean. Also check the B+ terminal on the alternator to make sure it's clean. By clean, I mean free of grime and corrosion.
Never go back to the first mechanic. He doesn't know what he's doing. A good mechanic can tell you in 10 minutes if it's the alternator or battery or both. Our trucks voltage regulation is not controlled by a regulator in the alternator. It's controlled by the engine control module (ECM) and Intelligent Power Distribution Module (IPDM).
The second mechanic knows what he's doing. If you don't have a mechanic, keep going to him. One thing I will recommend is to use a flooded lead acid battery. These are the old school type of batteries that have a liquid electrolyte. Do not use an AGM. The charging system in our trucks is not designed for an AGM battery. Our charging system, charges at too low of a voltage most of the time for an AGM. An AGM needs 13.8 to 14.6 Volts at all times or else it will fail to charge properly and die prematurely.
The reason why the system voltage goes down on your truck when you turn on the air conditioning is because the A/C is pulling more amps (current), so the voltage goes down. To show you this is what's going on, put a voltmeter on the battery and make note of the voltage. While looking at the voltmeter, have someone start the truck, and you will see the voltage drop while the starter is turning. That's because the starter is pulling a lot of amps to turn the engine to get it started. If you have the min/max function on your multimeter, use it and you will see how low the voltage goes. The A/C does the same thing to the alternator when you turn it on. The voltage drops but the current (amps) goes up. Put an amp clamp on the thick wire that goes from the alternator to the battery and you will see this.
Just make sure you keep the top of the battery, it's terminals, and anything connected to it's terminals clean.
I did take it to the dealer and he confirmed that as you say this is how this system works.
I know that the voltage goes down when on start up or turning on AC . When I turn on the AC or on start my old 2006 Honda Accord four-cylinder, of course the charging rate down, then goes right back up to 14.2 charging rate almost immediately afterwards and keeps a steady 14.2 charging rate. Of course, also upon startup, it acts the same way.
Also, my friend’s old 2004 Chevy, same thing he starts it up, turn the on l AC, voltage drops and then the charging rate goes right back up. Naturally the voltage drops and then the meter goes back into the original charging range. Obviously, these old vehicles don’t have ECM’s. It just seemed odd it doesn’t work this way on the Frontier. I certainly appreciate your information. I feel better that the dealer also confirmed what you say as far as the system working the way it does. The mechanic did put an AGM battery in the 2010 Frontier at my request due my thinking that is the better battery and an improvement over the old type, but I guess for this application it’s not the best choice according to you. He didn’t seem aware of that. Also, he made me skeptical of him, even though he was correct, because he really didn’t seem sure of himself and even asked me if I checked with the dealer to see if there was a bulletin out this being a problem.
@@mannymanano Every AGM battery has a label on it warning you about the 13.8V to 14.6V voltage requirements. I bought one at O'reillys and it only lasted a little less than 3 years. I bought it before I knew about the voltage requirement. The regular flooded lead acid AC Delco lasts me a little over 5 years.
Hello i have BMW 730d 2008 and when i start the car it says Alternator fault and some times indicators left or right failure but for short time like seconds ??????!
Very informative. 🎉
What about fuses?
I have an issue where I would start the car and the battery light would stay on. I then turn it on and off 3-4 times then on the 5th try, the battery light goes away. I then drive for 10 minutes without the light on dash. I then park somewhere turn it off. Once I turn it back on the light comes on again.
I just used a battery charger on my CTs vsport last night because it was reading 12.4 and I plugged right on the battery did I hurt the battery
Question my BMW battery dies if I don’t drive it every day. 1 day starts like it should but if I wait 2 days the battery is dead. Have replaced the battery twice. How do I check to see if the alternator is still producing or drawing amps with the car off ?
You can do the same test Nate does around the 5-minute mark to verify if your alternator is charging the battery while running. 13.8-14.8 volts is an acceptable range for a healthy charging system.
Please help, my car charging lamp blinks on an off while running. Battery is not charging. When a new alternator is add it becomes ok for few days an the same problem comes again, please help