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I know this video is 2 years old.. but i hope the owner of this car sued the original mechanic/shop for misdiagnosing his vehicle and all the labor costs! Great work my friend. Love Snap On Tools !
i have trouble thinking about my friends Hyundai elantra sir.the battery goes off when the engine runs and there's magnet in pulley and yet i have a 10v reading and the battery cannot fully charge.why is that?
I actually learned something! Thank you. I liked the "let's learn together approach" for this particular problem. You used your experience to lead you--and us--in the right direction and it paid off. Well done, sir!
I am a dealer tech (for a European brand). In about 2013 our manufacturer changed the out put of the alternator to keep the battery at about 12v and not much higher. This extends the life of the battery. They said the battery can last an additional 30% or something like that. Keeping the battery at 12v instead of 13 to 14 volts keeps it cooler and extends the life of the plates. Good video, I did not know hyundai did this as well.
I know it's been 2 years and I don't know if you'll see this question, but this is happening to me right now. If you don't mind my asking, what manufacturer?
I had a Ford that took me 4 alternators to finally get one that would charge. 2 Aftermarkets 1 Motorcraft (still didn't work) 1 one last aftermarket. I doubted my diagnosis a few times but once we got one with the correct regulator inside it worked like it was new.
I had a similar issue a couple of years ago, one of the guys at the shop changed out 2 alternators in 2 days and the car got towed back the day after fitting each unit after breaking down with a flat battery. I had to check it out after it got towed back the second time and it was charging fine, both loaded and unloaded, I couldn't find anything wrong with it. Then I got to thinking, it was the middle of winter at the time so there would be a big continuous load on the alternator, so I let the engine run for 15 mins with the heater fan and lights on, came back and battery voltage was 12.something volts. Turns out part of the cable from the alternator to battery positive was corroded so the voltage drop got worse the longer the alternator was under load. Since then, I always load the alternator for at least 10 mins after the initial check.
@@sh2697 The battery was being drained because the alternator couldnt charge it. The alternator was outputting 14.5 volts but the battery was getting less than 11volts (I'm assuming less than 11v because the lowest I measured was 11.3ish) while the customer was driving through the night, they noticed the headlights were getting dim (again), they stopped and the car and it wouldn't start again because the battery was flat. There was so much resistance in the corroded cable, it partially melted the junction box
I’m pretty sure something like that is causing my alternator to not charge the battery. I’m dreading trying to find the problem. Alternator bench tested fine. 3 new batteries. Alternator isn’t charging the battery.
Smart systems are stupid back in the day if yiu needed a alternator or battery you go buy it and problem solved. Never buying new cars ever im keeping only my good 90s cars
I had these same symptoms on my F150. Threw me for a loop and and at first I swapped the alternator as well which didn't fix it. The actual cause for me was a bad ground from the engine to battery. This was tripping the computer up and when you had lights and heater on it couldn't source enough amps through the bad ground to keep up. So I just added an extra ground cable right to the engine mount of the alternator and ran it to the negative on the battery and not only did it fix the voltage problem but now my starter is much faster as well. I'm in the rust belt of Illinois so I am sure the original engine to frame/battery ground is corroded or gone. This situation is easy to test if you just use a set of jumper cables and only use the negative leads and connect one to batter and the other to a solid connection on the engine.
@@bruhbruhh5103 Run from negative to the mounting bolt on the alternator. Any bolt on the motor that isnt going to cause a leak or problem will work. Motors are isolated by rubber mounts so they need a ground strap to keep them connected electrically to the frame and battery. When the oem ground strap rusts and fails you get random electrical problems. Usually those oem straps are in the back or bottom of the engine and can be a pain to get to. You are just accomplishing the same thing but up top where its easier to get at and maintain. You are not disturbing the red positive wire on the alternator. You are just looking to add ground path to the engine.
Had a customer back in the day, replaced alternator, regulator and battery. Battery would still be dead after sitting overnight. When he dropped the car off he left the keys in the glove box. First thing I noticed was the switch for the glove box light was dangling behind the glove box. Turns out the trunk light was always on too.
An excellent video. Like the man says Do your homework. Some people's comments of changing out three batteries and alternators. That shows no knowledge of the issues. I have learned something from this video. Thank you.
Great advice = do your research BEFORE changing parts ! As long as the battery was checked and no parasitic drain it should be fine . Today's JOKE : the customer asked the other shop if they checked for parasitic drain . They told him to " Call a PLUMBER " !
Good job man. You just showed again scan tools are a great help . But we do have to know how the systems work in order to come up with the most accurate diag. That means we need access to information . Newer cars are loaded with high tech. We have to educate ourselves more than ever. God bless.
Most of the computer controlled alternators these days have load dependant charging, emmisions and efficiency and all that are a big thing, no point in driving a load that isn't needed
@@sh2697 The alternator on the vehicle was working correctly, under conditions when there was minimal electrical consumption, the control system was turning the alternator off, some people don't know of this function on some modern vehicles and it can be mistaken as a faulty alternator.
@@2secondslater Spot on! It's been available on cars for a few yeas. My first EFI car (manufactured in 2006) had a computer controlled alternator. If you want to learn more about your car, download and read the manufacture's repair manual (one the one used by the dealership mechancis to repair your car). It contains heaps of useful info on how your car works!
I don't know in the US but in Europe that is a feature that most new cars have. I've tested that in a european 2013 ford focus (so 8 years ago). Ford calls that systen "micro-hybrid" because it recovers energy when you aren't accelerating. For the whole system to work, it has a controller that measures current going in and out of the battery and knows the charge. If the battery doesn't need to be charge, the voltage would be around 12.5V or something like that, even lower when the start&stop system stops the engine because all the electronics are working but the alternator is stopped. In this way the car consumes less fuel. If you're driving around and lift the accelerator pedal, the system engages the alternator and it'll go to 14.4V or so because that is "free energy". In the case that the battery is too low, the system will charge the battery and you'll see 14.4V even at idle and the start&stop system won't work until the battery is charged to a certain level. You have to be careful when changing the battery though. You have to reset this controller (at least in the ford focus) in order for the system to recognise that it has a new battery. We had to change the battery once and I told the techinician to do it (they had a tool from EXIDE to do this) but he insisted it wasn't necessary. The result was that 2 months later the battery was dead. They replaced the battery in warranty and reseted the system and everything worked fine then.
If you feel like this video helped out, feel free to support the channel by donating. Just one click away on the link below, to help support the channel :) www.paypal.me/ozmechanics
My 06 Nissan Frontier 4.0L V6 will start out at 14.0 volts then ramp down to 12.9. When lights, A/C, wipers, etc are added, it still maintains 12.9 to 13.0 but the current output increases until the loads are removed. It's normal for the system to do this. Good diagnosis Oz.
Yup, they aren't going to charge more if there is no need. Back in my day we had older testers that had carbon pile testers in them. One could turn up the resistance and if the alternator started to charge more then one knew that it was ok. What was fun is to increase the resistance to see how good they were to the point they went below 12v. If that eng was still running then you knew the alt was really good. If it went below 12v rather early then you knew you pretty much had had brushes. Good job in diagnosing that no problem issue !
Yea, I got my butt wiped on one when I was so focused it was like a regular alternator. And I didn’t help I didn’t have service information in my finger tips
@@OzMechanics yeah, painful to deal with the first time if you aren't aware of them 😂😂, I had issues with one a long time ago and just assumed it was a faulty regulator 😂 swap it out....still faulty.....then I started hunting...... Always pays to research before throwing parts at it.....especially 3 alternators😂😂😂
I believe the first problem was an alternator. But after the new alternators were installed he would check the voltage and notice it would be 12 volts and he would take it back to get it replaced
@@OzMechanics well I guess we all have to learn the hard way. I got caught on my honda with this issue as well, change the Alternator and battery bc they were both bad and had the same readings and started testing based of of the readings, bench tested the Alternator and said hmmm...so I went and used my buddy subscription to pro demand and learned about smart charging. The vehicles are becoming to smart..IMO making them stupid lol. Thanks for what you do!
There was no problem. The customer was just concerned about the vehicle only charging at 12.6 volts and not 14. But because this is a smart charge system, the car is working perfectly
I noticed you were from Texas. I live in League City. I just replaced my alternator on my 2013 Hyundai Elantra GT with a remanufactured one from Amazon. It worked perfectly for about an hour but failed catastrophically within about an hour. At this point I don't know if the new alternator failed or something else is causing it to fail. I'm going to have the new alternator checked today and go from there. If I can't figure it out I might come see you.
Morning Kevin I just recently recorded a video where the customer bought some amazon spark plugs and they ended being cheap aftermarket knock off that had the OEM name on them. Caused a lot of problems
I just ran thru 2 alternators thinking they were broken on my 2012 civic because the battery died after running the AC and music for 5m idling. Because the headlights weren't on, it didn't trip up to 14V and that was apparently enough to drain it.
Yes my 2012 Honda Civic does exactly the same thing as soon as you start the car the alternator is charging the battery to 13.5 -14.7 and after a minute or 2 it drops the voltage back to about 12.3-12.6 I almost changed the alternator after replacing my dead battery which was the original problem and did a test by simply turning on the air conditioner and seeing the voltage jump to 14.5-14.7 and later letting the alternator charge the battery it went down back to 12.3 -12.6 volts and as long your battery light on your dash does not illuminate your good to go but thank you for proving that with you scanner as I don’t have one 😊
Great video, I thought my alternator was not charging would stay around 12 had to restart the car 3 times before the voltage would go around 14! guess it saw batterie had gone down from me starting the car 3 times in a row before it considered turning up the demand on the alternator. Great and informative video!
@@OzMechanicsYeah, I did. Great video and great job doing thorough tests and research on a customer complaint. It's just that I think a faulty ELD will make the ECU command a lower duty cycle (or higher, sometimes). There have been such cases on some Honda's. So, maybe a research on the ELD signals could be for another video? Just a suggestion. Cheers.
In the issue customer thought that because the battery was charging at 12 volts at idle that the alternator was bad. The thing is I found that this car is has smart charge and I performed test that showed 12v at idle is normal. Did you see that part of the video ?
This explained a lot for me - thanks for the video sharing the knowledge. I have a Volvo C30 1.6D Drive (Full of eco baloney). First alternator failed spectacularly. No question on that one. Second failed after 5 months - was a cheap unbranded replacement. Third one which is the current one displays the same behaviour as the vehicle in this video. Smart alternator. As low as 12.7 a idle, atnd tops at 14V under load. Indy garage that fitted this latest one wasn't convinced it was working correctly until I showed them this video. They learned something too...
If Exciter wire is not getting 12V then it’s not powering up the voltage regulator therefore it won’t keep the battery at a good voltage level . It’ll either over charge or not give enough charge to the battery
Well In this vehicle due to all the economy features. They have a smart charge system that stays at 12v at idle with no load and jumps up when ever load is applied
So, I'm not sure what the customer's real issue was. Was his battery going dead or something else. Also, the battery and alternator could be tested at Advance, Autozone or Napa.
I have a brief meeting explanation in the description explaining that. And remember customer just came in to ask why was it charging at 12.5 volts and in this video I verified that. Thanks again for watching
I wouldn’t this applies to newer vehicles. But I will be filming a video tomorrow on an older vehicle that has had 3 alternators replaced and it’s an older one
Actually wondering why did the customer checked the voltage when there is no fault codes or battery issues, he might just be a really curious one. Also is this what hyundai calls Alternator management system?
So he explained to me that his car died use and thought it might be the battery or alternator. But we found out he just left his lights on. But he did test the running voltage that time
So, I have this same issue battery has died 3 times. Not sure where to start. I don't have all of the fancy scan tool but I placed a volt meter reader in the cigarette light and my car does this same thing.
I have a 2007 Hyundai Elantra and I've run into the same problem. As long as I'm driving the alternator charges and keeps everything running. However my battery dies all the time. I have a new battery two new alternators new terminals any new alternator plug. Still can't find the problem.
Part of the "squeeze every mile/km out of that gallon/liter of gas" computer programming. Depending on the type of battery, it may also give longer battery life. Looks like a good method of controlling battery charging but this needs to be in the owner's manual: "Battery voltage is not always 13.8 volts. It varies with the electrical load and the battery's state of charge. Voltages of 12.5 to 14.4 are normal when the engine is running." Me? I've built a couple of small solar systems (shed lighting, "Wait until daylight" backup power) so I'm very aware of the trade-offs in battery charge level versus battery life. My previous set of AGM batteries (typical life of 5-7 years) were replaced a few months before their 9th birthday.
I also see the alternator has an over running clutch on the pulley. These allow the alternator to spin free at certain times and can also show low voltage under no load. I should add that by accelerating the engine, you should see the voltage increase and decel will let the alternator free wheel and lower voltage.
Great work man. It’s funny that we’ve had smart alternators for quite some time but people still don’t realize it. Superb explanation of the system and showing how it works. One question I have. Did the versus not have the PIDs for duty cycle?
Interesting troubleshooting and analysis of the data. What started all the replacement alternators in the first place ? Customer measuring the 12.3 V and then assuming that’s a problem?
The first time they replaced the battery, I’m sure it was probably because of a bad alternator. But the customer ended up telling me later on that he checked it out because his battery was drained, but told me that he believed he left the lights on. I verified That with a parasitic draw test and also the alternator test that was done on the video.
@@OzMechanics Thanks for your follow up reply. I have a 2015 Accord and connecting my DMM a few times noticed similar voltage readings. Didn’t realize PCM controls alternator voltage with newer cars.
My Ford has a 'generator voltage desired' pid. Is that equivalent to the duty cycle desired (obviously in a different format VDC vs DC%) in that hyundai or is that not a fair 1:1 comparison in one way or another?
No issues it's called a smart alternator as it's got a little black box on the negative terminal side witch tells the alternator to charge the battery at a higher or lower voltage
Damn bro, you saved me from changing my alternator from a 2nd time! I just got my alternator rebuilt and was about to take it back because I wasn’t getting a higher voltage than 12.5 until I did the battery load test and the voltage started going up like the video. I got a Honda accord 2016. What Honda were you referring too?
Awesome 😎 glad this video helped you out. I believe it was a Hyundai Electra if I’m not mistaken. Yea, these smart charge systems can take you on a loop. Thanks for watching
My check charging system is on in my 2012 civic si. I replaced the alternator and it fixed it for 3 months and then came back on and now can't drive it . Keeps not charging my battery
Yes Nice Diagnosis and research , i always like to see my Alternator Compensating Voltage whilst under load ,,,enjoyed The video well explained ...........
So I'm assuming that to keep it charging - the owner must drive with headlights on all the time . Is that correct? Although one of your commentators said his client drove through the night and noticed his lights dimmed and then engine would not start. Still confused !!
This is a smart charge system. So on this exact vehicle the alternator doesn’t charge at full potential (14v) when the vehicle is at idle with no loads (example. Headlights, and wipers or ac on) because the vehicle doesn’t demand a lot of energy. But once the loads are turned on that’s when the voltage jumps on these systems. So when the customer tested the battery voltage, 1st he didn’t know this vehicle is equipped with a smart charge system. And was thinking this was a conventional alternator that always pushes 14v at all times.
Thanks , I think I understood that bit. So you are confirming that the reason the customer had had 3 dead new batteries was due to driving on idle with no load on the electrical system. @@OzMechanics
Patrick. The reason Oz's customer replaced the alternator 3x was that he (or his mechanic) didn't understand the design & operation of the Hyundai AMS system. He was thinking older, non smart charging system design, and expected to see a fixed voltage set point (14.xx volts) at all times. The HMA AMS will maintain a charging voltage of 12.2-12.7 volts during no-load condition when battery is at 100% (high) State Of Charge (SOC).
Here's the problem with dropping the voltage that low (12.4v, 34% duty cycle). The battery is discharging. If you were to use a hydrometer, you need not see a fully charged battery.
With no loads that really wouldn’t effect the battery. Once we get a load in the mix the battery voltage jumps to replenish the low voltage. Thanks for watching
Early on into the video i thought to myself... What if thats just normal operation of the alt and the owner doesnt know any better... 😂 first time i ran into this issue on a altima i almost put a alternator on it till I figured out thats normal. 👍
That obd looks expensive and very informative. So it charging at a higher rate is normal when under load I had replaced 2 alternators and changed brand on the third one to get constant 12v even under load my god your awesome
Thank you for the video, I'm in the middle of this on an '04 Corolla. Can you remember if the customer's battery light was one? Mine is. I will check codes and repeat the drop tests. I replaced battery and alternator already. Thanks!
Were you able to watch the entire video ? It does show that it charges the battery once we put load to the vehicle… turning on light and the ac. This vehicle is equipped with a smart charge system that only out puts small voltage at first when the vehicle is not needing a lot of power but once we add more load to it. That’s why it wakes up the alternator to produce more voltage
@OzMechanics I see, sry I'm mechanically inclined lol I've been having this issue for a few years n can't get it figured out.. also my toyota doesn't have ac. It's a 98 camry.
@@sanjayjames1778 I've been doing this for 55 years I'm retired I've got an 05 Kia Rio I'm on my third alternator of course the postal system damaged it in shipment and I sent one back but I've had the same problem charging for a while works for a week or two and then quits and then it doesn't charge anymore so I was going to replace all of my cables and all of my ground straps but I don't see anything on any cable that looks like a sensor
There was no problem when I got the vehicle. The customer was worried that the vehicle was charging at 12v not aware that this vehicle has a smart charge alternator. I explained how the system works on the video. As on the first time he replaced the alternator I’m not too sure why it was replaced.
No. If you carefully watch the entire video, you'll see Oz determines that this Hyundai AMS charging system is functioning normally. ua-cam.com/video/bgyWB8OtfKM/v-deo.htmlsi=1C68tu7giN9KRmyQ
It's the smart alternator design extra dumb they start out at regular voltage and then decrease when there's no load and even when you're driving it only will stay at the higher voltage for a little bit
I would say normal .. the voltage spikes on start to recharge the battery from taking the power out of the battery to start it Also the interior lights come on And the computer system reads cold starts etc
@@smokenbudesq because he kept on reading 12.6 volts. But that’s how the vehicle charges. It’s a smart charge system. Was there a part on the video you didn’t understand? Seeing if I can help out
@@OzMechanics OK SO IT WASN'T THE BATTERY LOSING POWER WHY EVEN BOTHER IDIOTIC . HE SHOULD HAVE RESEARCHED IT IN THE MANUAL. SO OBVIOUSLY WASTED MY TIME AND YOUR TIME HOPE YOU CHARGED HIM.
@@smokenbudesq to be honest, some seasoned techs have been burned by these smart charge system. And I was one of them. I just got to focused on pats hat was infront of me and just kept on thinking, “ vehicles should be charging at 14V”. After that I make sure to read service info now to really understand the system I’m working on. Thanks for watching
Great video Oz, this is the 1st alternator video I've ever seen on UA-cam indicating ~ 12.4 Vdc at Idle. I believe most of the Alternator videos I've seen would have called this a Bad Alternator, do you know if a 2006 Toyota Tundra would operate like this Hyundai, i'm always monitoring the Alternator voltage and it seems Low ~ 12.6 to 12.4 at idle but when cruising and off idle voltage jumps up to 13.6 to 14.1. Thanks again for your video.
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I know this video is 2 years old.. but i hope the owner of this car sued the original mechanic/shop for misdiagnosing his vehicle and all the labor costs! Great work my friend. Love Snap On Tools !
Scan tool link was not like the one you were using. What snapon do you have
i have trouble thinking about my friends Hyundai elantra sir.the battery goes off when the engine runs and there's magnet in pulley and yet i have a 10v reading and the battery cannot fully charge.why is that?
😂 The other shops replaced 3 alternators and couldn’t figure that out. Good job! 👍
Looks like they replaced it with an old dusty alternator, three times.
I actually learned something! Thank you. I liked the "let's learn together approach" for this particular problem. You used your experience to lead you--and us--in the right direction and it paid off. Well done, sir!
Thanks for watching
I am a dealer tech (for a European brand). In about 2013 our manufacturer changed the out put of the alternator to keep the battery at about 12v and not much higher. This extends the life of the battery. They said the battery can last an additional 30% or something like that. Keeping the battery at 12v instead of 13 to 14 volts keeps it cooler and extends the life of the plates. Good video, I did not know hyundai did this as well.
Did they go to AGM batterys?
@@ScottDLR some use AGM, but some still used lead acid. Newer use lithium ion. As well we use a new 48 volt lithium ion
I know it's been 2 years and I don't know if you'll see this question, but this is happening to me right now.
If you don't mind my asking, what manufacturer?
@@soundfarm8814 Mercedes Benz
what about is the changing ligth is on in the dashboard?
I had a Ford that took me 4 alternators to finally get one that would charge. 2 Aftermarkets 1 Motorcraft (still didn't work) 1 one last aftermarket. I doubted my diagnosis a few times but once we got one with the correct regulator inside it worked like it was new.
Must have been an 06 mustang gt
That was pretty cool to see the graph confirm the operation.
I had a similar issue a couple of years ago, one of the guys at the shop changed out 2 alternators in 2 days and the car got towed back the day after fitting each unit after breaking down with a flat battery.
I had to check it out after it got towed back the second time and it was charging fine, both loaded and unloaded, I couldn't find anything wrong with it. Then I got to thinking, it was the middle of winter at the time so there would be a big continuous load on the alternator, so I let the engine run for 15 mins with the heater fan and lights on, came back and battery voltage was 12.something volts. Turns out part of the cable from the alternator to battery positive was corroded so the voltage drop got worse the longer the alternator was under load.
Since then, I always load the alternator for at least 10 mins after the initial check.
so if it broke down, may i ask what the problem was
@@sh2697 The battery was being drained because the alternator couldnt charge it. The alternator was outputting 14.5 volts but the battery was getting less than 11volts (I'm assuming less than 11v because the lowest I measured was 11.3ish) while the customer was driving through the night, they noticed the headlights were getting dim (again), they stopped and the car and it wouldn't start again because the battery was flat.
There was so much resistance in the corroded cable, it partially melted the junction box
Great advice, sir. Thanks!
I’m pretty sure something like that is causing my alternator to not charge the battery. I’m dreading trying to find the problem. Alternator bench tested fine. 3 new batteries. Alternator isn’t charging the battery.
Smart systems are stupid back in the day if yiu needed a alternator or battery you go buy it and problem solved. Never buying new cars ever im keeping only my good 90s cars
I had these same symptoms on my F150. Threw me for a loop and and at first I swapped the alternator as well which didn't fix it. The actual cause for me was a bad ground from the engine to battery. This was tripping the computer up and when you had lights and heater on it couldn't source enough amps through the bad ground to keep up. So I just added an extra ground cable right to the engine mount of the alternator and ran it to the negative on the battery and not only did it fix the voltage problem but now my starter is much faster as well. I'm in the rust belt of Illinois so I am sure the original engine to frame/battery ground is corroded or gone. This situation is easy to test if you just use a set of jumper cables and only use the negative leads and connect one to batter and the other to a solid connection on the engine.
Clever! I like it!
Thanks for information
Ok ok let's try it.
So I can run a cord from the negative to the alternator on top of the over wire?
@@bruhbruhh5103 Run from negative to the mounting bolt on the alternator. Any bolt on the motor that isnt going to cause a leak or problem will work. Motors are isolated by rubber mounts so they need a ground strap to keep them connected electrically to the frame and battery. When the oem ground strap rusts and fails you get random electrical problems. Usually those oem straps are in the back or bottom of the engine and can be a pain to get to. You are just accomplishing the same thing but up top where its easier to get at and maintain. You are not disturbing the red positive wire on the alternator. You are just looking to add ground path to the engine.
Dang you went above and beyond explaining this one! Thanks! 👍
I just felt I had to explain piece by piece to really get to the point of this issue
Had a customer back in the day, replaced alternator, regulator and battery. Battery would still be dead after sitting overnight. When he dropped the car off he left the keys in the glove box. First thing I noticed was the switch for the glove box light was dangling behind the glove box. Turns out the trunk light was always on too.
Parasitic draw....
Thank you for your patience and diligence. Yr tenacity shows great job 👍
Might it have been wise to turn lights, heater fan, rear defroster, ecg and then checked to see that alternator puts out amps it is rated for?
An excellent video. Like the man says Do your homework. Some people's comments of changing out three batteries and alternators. That shows no knowledge of the issues. I have learned something from this video. Thank you.
Great advice = do your research BEFORE changing parts ! As long as the battery was checked and no parasitic drain it should be fine . Today's JOKE : the customer asked the other shop if they checked for parasitic drain . They told him to " Call a PLUMBER " !
I could not really figure out what the actual problem was after running these tests please help me understand
Good work
Good job man. You just showed again scan tools are a great help . But we do have to know how the systems work in order to come up with the most accurate diag. That means we need access to information . Newer cars are loaded with high tech. We have to educate ourselves more than ever. God bless.
That is 10000% true.
Most of the computer controlled alternators these days have load dependant charging, emmisions and efficiency and all that are a big thing, no point in driving a load that isn't needed
so the car didnt charge. something was wrong. Can someone tell me what was replaced? I really like the snap on tool you have
@@sh2697 The alternator on the vehicle was working correctly, under conditions when there was minimal electrical consumption, the control system was turning the alternator off, some people don't know of this function on some modern vehicles and it can be mistaken as a faulty alternator.
What he said ^ I was curious to see your test method txt book checking , good vid
Its called elc.engine load detector
@@2secondslater Spot on! It's been available on cars for a few yeas. My first EFI car (manufactured in 2006) had a computer controlled alternator. If you want to learn more about your car, download and read the manufacture's repair manual (one the one used by the dealership mechancis to repair your car). It contains heaps of useful info on how your car works!
You should check voltage drop while the alternator is
loaded-- carbon pile, accessories .etc.
Alternators will not charge 14v all the time while running to avoid damaging the battery in certain vehicles. Great work!
I don't know in the US but in Europe that is a feature that most new cars have. I've tested that in a european 2013 ford focus (so 8 years ago). Ford calls that systen "micro-hybrid" because it recovers energy when you aren't accelerating. For the whole system to work, it has a controller that measures current going in and out of the battery and knows the charge. If the battery doesn't need to be charge, the voltage would be around 12.5V or something like that, even lower when the start&stop system stops the engine because all the electronics are working but the alternator is stopped. In this way the car consumes less fuel. If you're driving around and lift the accelerator pedal, the system engages the alternator and it'll go to 14.4V or so because that is "free energy". In the case that the battery is too low, the system will charge the battery and you'll see 14.4V even at idle and the start&stop system won't work until the battery is charged to a certain level.
You have to be careful when changing the battery though. You have to reset this controller (at least in the ford focus) in order for the system to recognise that it has a new battery. We had to change the battery once and I told the techinician to do it (they had a tool from EXIDE to do this) but he insisted it wasn't necessary. The result was that 2 months later the battery was dead. They replaced the battery in warranty and reseted the system and everything worked fine then.
Really interesting and great info, thanks!
Had the same thing on a Honda. Smart charging. That system out smarted me
Yep, that’s the first one that kicked my rear end
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Thanks! Been servicing cars for many years and learned new information here.
My 06 Nissan Frontier 4.0L V6 will start out at 14.0 volts then ramp down to 12.9. When lights, A/C, wipers, etc are added, it still maintains 12.9 to 13.0 but the current output increases until the loads are removed. It's normal for the system to do this.
Good diagnosis Oz.
The more challenging task: writing up the repair order in language the customer can comprehend
That was really hard. But I will show them this video so that can help out as well
Wow did not expect that! Learned something new today.
Yep, in automotive, it’s always some new and fun to find out
Honest mechanic👌
Nice breakdown I had same situation on nissan altima , alternator output adjust to the load great job
Great video, clear concise and presented extremely well..... many thanks! 👍
I don’t see how shops are still missing things like this. Smart charging systems have been around for years now.
Very informative. I wish your shop was closer to my location. Thank you!
Nice job , Research pay's off .
Gotta love computer controlled alternators,,,,I also had my ass handed to me on a 2016/chev 1500 pick up !
Nice video. You see this on ford's a lot. The commutation wire going to the ecu brakes lite comes on and out put from altanator is 14 + voltage.
Yup, they aren't going to charge more if there is no need. Back in my day we had older testers that had carbon pile testers in them. One could turn up the resistance and if the alternator started to charge more then one knew that it was ok. What was fun is to increase the resistance to see how good they were to the point they went below 12v. If that eng was still running then you knew the alt was really good. If it went below 12v rather early then you knew you pretty much had had brushes. Good job in diagnosing that no problem issue !
Thank you this was extremely helpful
As a tech myself I never knew this
Field sensing alternators are suppppeerrr common on late model cars, good trick for beginners to check that first
Yea, I got my butt wiped on one when I was so focused it was like a regular alternator. And I didn’t help I didn’t have service information in my finger tips
@@OzMechanics yeah, painful to deal with the first time if you aren't aware of them 😂😂, I had issues with one a long time ago and just assumed it was a faulty regulator 😂 swap it out....still faulty.....then I started hunting...... Always pays to research before throwing parts at it.....especially 3 alternators😂😂😂
That's how the manufacturers up the gas mileage by adjusting the field current with the pcm.
Great video, just curious was the customer changing the Alternator based off of just the voltage readings? Or could there be a Parasitic draw?
I believe the first problem was an alternator. But after the new alternators were installed he would check the voltage and notice it would be 12 volts and he would take it back to get it replaced
@@OzMechanics well I guess we all have to learn the hard way. I got caught on my honda with this issue as well, change the Alternator and battery bc they were both bad and had the same readings and started testing based of of the readings, bench tested the Alternator and said hmmm...so I went and used my buddy subscription to pro demand and learned about smart charging. The vehicles are becoming to smart..IMO making them stupid lol. Thanks for what you do!
@@richardmitchell7836 yep, that’s how I learned about this. Honda
But, what is his problem? Is his battery not charging up? Not starting car at times? Has the battery been load tested and battery connections cleaned?
There was no problem. The customer was just concerned about the vehicle only charging at 12.6 volts and not 14. But because this is a smart charge system, the car is working perfectly
I noticed you were from Texas. I live in League City. I just replaced my alternator on my 2013 Hyundai Elantra GT with a remanufactured one from Amazon. It worked perfectly for about an hour but failed catastrophically within about an hour. At this point I don't know if the new alternator failed or something else is causing it to fail. I'm going to have the new alternator checked today and go from there. If I can't figure it out I might come see you.
Morning Kevin I just recently recorded a video where the customer bought some amazon spark plugs and they ended being cheap aftermarket knock off that had the OEM name on them. Caused a lot of problems
Learned something new. Never seen that....
A data driven tech... wow! Good stuff, although that seems a bit dicey to me if you use vehicle for short, low load trips.
I just ran thru 2 alternators thinking they were broken on my 2012 civic because the battery died after running the AC and music for 5m idling. Because the headlights weren't on, it didn't trip up to 14V and that was apparently enough to drain it.
Yes my 2012 Honda Civic does exactly the same thing as soon as you start the car the alternator is charging the battery to 13.5 -14.7 and after a minute or 2 it drops the voltage back to about 12.3-12.6 I almost changed the alternator after replacing my dead battery which was the original problem and did a test by simply turning on the air conditioner and seeing the voltage jump to 14.5-14.7 and later letting the alternator charge the battery it went down back to 12.3 -12.6 volts and as long your battery light on your dash does not illuminate your good to go but thank you for proving that with you scanner as I don’t have one 😊
Great video, I thought my alternator was not charging would stay around 12 had to restart the car 3 times before the voltage would go around 14! guess it saw batterie had gone down from me starting the car 3 times in a row before it considered turning up the demand on the alternator. Great and informative video!
Thank you Oz. Good job. Have a blessed and safe week to you and your family.
what was the customer complaint ?
That it was charging at 12.6 volts. And also the battery died. But he ended up telling me that he might have left the lights on
Likely a problem with the ELD?
Did you watch the entire video ?
@@OzMechanicsYeah, I did.
Great video and great job doing thorough tests and research on a customer complaint.
It's just that I think a faulty ELD will make the ECU command a lower duty cycle (or higher, sometimes). There have been such cases on some Honda's.
So, maybe a research on the ELD signals could be for another video?
Just a suggestion.
Cheers.
What was the issue then
In the issue customer thought that because the battery was charging at 12 volts at idle that the alternator was bad. The thing is I found that this car is has smart charge and I performed test that showed 12v at idle is normal. Did you see that part of the video ?
Why did the car owner bring it to your shop? What problem did they want you to fix?
Right?????????
This explained a lot for me - thanks for the video sharing the knowledge.
I have a Volvo C30 1.6D Drive (Full of eco baloney).
First alternator failed spectacularly. No question on that one.
Second failed after 5 months - was a cheap unbranded replacement.
Third one which is the current one displays the same behaviour as the vehicle in this video. Smart alternator. As low as 12.7 a idle, atnd tops at 14V under load.
Indy garage that fitted this latest one wasn't convinced it was working correctly until I showed them this video. They learned something too...
What is the rule of thumb for "Old School " non ECM/PCM cars? I believe that it should be ~13.6V at idle regardless of load.
What was the customer complaint if the system is working properly? I would assume battery drain overnight.
My Honda Accord Sport does this. So I knew immediately they got ripped off =). Subbing brother.
If Exciter wire is not getting 12V then it’s not powering up the voltage regulator therefore it won’t keep the battery at a good voltage level . It’ll either over charge or not give enough charge to the battery
Well In this vehicle due to all the economy features. They have a smart charge system that stays at 12v at idle with no load and jumps up when ever load is applied
So, I'm not sure what the customer's real issue was. Was his battery going dead or something else. Also, the battery and alternator could be tested at Advance, Autozone or Napa.
I have a brief meeting explanation in the description explaining that. And remember customer just came in to ask why was it charging at 12.5 volts and in this video I verified that. Thanks again for watching
that was a useful insight.
Could you tell us about the current at the moment of cranking?
I wonder if a 2004 Ford focus se 2.3l has the same problem
I wouldn’t this applies to newer vehicles. But I will be filming a video tomorrow on an older vehicle that has had 3 alternators replaced and it’s an older one
if the alternator is good,then what is causing the voltage to drop? how about the wiring?
Did you watch the whole video ?
Actually wondering why did the customer checked the voltage when there is no fault codes or battery issues, he might just be a really curious one. Also is this what hyundai calls Alternator management system?
So he explained to me that his car died use and thought it might be the battery or alternator. But we found out he just left his lights on. But he did test the running voltage that time
@@OzMechanics poor Alternator took the blame 😂
So, I have this same issue battery has died 3 times. Not sure where to start.
I don't have all of the fancy scan tool but I placed a volt meter reader in the cigarette light and my car does this same thing.
I have a 2007 Hyundai Elantra and I've run into the same problem. As long as I'm driving the alternator charges and keeps everything running. However my battery dies all the time. I have a new battery two new alternators new terminals any new alternator plug. Still can't find the problem.
@@michelesalas7326 may be u should search for parasite leak
Part of the "squeeze every mile/km out of that gallon/liter of gas" computer programming. Depending on the type of battery, it may also give longer battery life.
Looks like a good method of controlling battery charging but this needs to be in the owner's manual: "Battery voltage is not always 13.8 volts. It varies with the electrical load and the battery's state of charge. Voltages of 12.5 to 14.4 are normal when the engine is running."
Me? I've built a couple of small solar systems (shed lighting, "Wait until daylight" backup power) so I'm very aware of the trade-offs in battery charge level versus battery life. My previous set of AGM batteries (typical life of 5-7 years) were replaced a few months before their 9th birthday.
I also see the alternator has an over running clutch on the pulley. These allow the alternator to spin free at certain times and can also show low voltage under no load. I should add that by accelerating the engine, you should see the voltage increase and decel will let the alternator free wheel and lower voltage.
Wud that battery light on discharge the battery at night time as it sits?
Great work man. It’s funny that we’ve had smart alternators for quite some time but people still don’t realize it. Superb explanation of the system and showing how it works. One question I have. Did the versus not have the PIDs for duty cycle?
That is right. The verus only showed desired, not the actual duty cycle
Interesting troubleshooting and analysis of the data. What started all the replacement alternators in the first place ? Customer measuring the 12.3 V and then assuming that’s a problem?
The first time they replaced the battery, I’m sure it was probably because of a bad alternator. But the customer ended up telling me later on that he checked it out because his battery was drained, but told me that he believed he left the lights on. I verified That with a parasitic draw test and also the alternator test that was done on the video.
@@OzMechanics Thanks for your follow up reply. I have a 2015 Accord and connecting my DMM a few times noticed similar voltage readings. Didn’t realize PCM controls alternator voltage with newer cars.
PMC on 2003 mini cooper
My Ford has a 'generator voltage desired' pid. Is that equivalent to the duty cycle desired (obviously in a different format VDC vs DC%) in that hyundai or is that not a fair 1:1 comparison in one way or another?
No issues it's called a smart alternator as it's got a little black box on the negative terminal side witch tells the alternator to charge the battery at a higher or lower voltage
What part of Texas are you in? Having an alternator issue right now.
Damn bro, you saved me from changing my alternator from a 2nd time! I just got my alternator rebuilt and was about to take it back because I wasn’t getting a higher voltage than 12.5 until I did the battery load test and the voltage started going up like the video. I got a Honda accord 2016. What Honda were you referring too?
Awesome 😎 glad this video helped you out. I believe it was a Hyundai Electra if I’m not mistaken. Yea, these smart charge systems can take you on a loop. Thanks for watching
My check charging system is on in my 2012 civic si. I replaced the alternator and it fixed it for 3 months and then came back on and now can't drive it . Keeps not charging my battery
Yes Nice Diagnosis and research , i always like to see my Alternator Compensating Voltage whilst under load ,,,enjoyed The video well explained ...........
So I'm assuming that to keep it charging - the owner must drive with headlights on all the time . Is that correct? Although one of your commentators said his client drove through the night and noticed his lights dimmed and then engine would not start. Still confused !!
This is a smart charge system. So on this exact vehicle the alternator doesn’t charge at full potential (14v) when the vehicle is at idle with no loads (example. Headlights, and wipers or ac on) because the vehicle doesn’t demand a lot of energy. But once the loads are turned on that’s when the voltage jumps on these systems. So when the customer tested the battery voltage, 1st he didn’t know this vehicle is equipped with a smart charge system. And was thinking this was a conventional alternator that always pushes 14v at all times.
Thanks , I think I understood that bit. So you are confirming that the reason the customer had had 3 dead new batteries was due to driving on idle with no load on the electrical system. @@OzMechanics
Patrick. The reason Oz's customer replaced the alternator 3x was that he (or his mechanic) didn't understand the design & operation of the Hyundai AMS system. He was thinking older, non smart charging system design, and expected to see a fixed voltage set point (14.xx volts) at all times. The HMA AMS will maintain a charging voltage of 12.2-12.7 volts during no-load condition when battery is at 100% (high) State Of Charge (SOC).
Here's the problem with dropping the voltage that low (12.4v, 34% duty cycle). The battery is discharging. If you were to use a hydrometer, you need not see a fully charged battery.
With no loads that really wouldn’t effect the battery. Once we get a load in the mix the battery voltage jumps to replenish the low voltage. Thanks for watching
do you think 2007 toyota rav4 2.4 work the same, i ready replace 3 alternator aftermarket end o got the same like your video..
Didn't know they do that but also you can graph the connector on the alternator to see the duty cycle
Early on into the video i thought to myself... What if thats just normal operation of the alt and the owner doesnt know any better... 😂 first time i ran into this issue on a altima i almost put a alternator on it till I figured out thats normal. 👍
Yea a Honda Civic made me learn that on some vehicles that this is normal
So, it's normal for voltage to be at 12 at idle with no load?
Yep, if you see the chart. At a duty cycle of around 30% the vehicle is charging at around 12.6 volts
That obd looks expensive and very informative. So it charging at a higher rate is normal when under load I had replaced 2 alternators and changed brand on the third one to get constant 12v even under load my god your awesome
Thank you for the video, I'm in the middle of this on an '04 Corolla. Can you remember if the customer's battery light was one? Mine is. I will check codes and repeat the drop tests. I replaced battery and alternator already. Thanks!
So why isn't it charging the battery?
Were you able to watch the entire video ? It does show that it charges the battery once we put load to the vehicle… turning on light and the ac. This vehicle is equipped with a smart charge system that only out puts small voltage at first when the vehicle is not needing a lot of power but once we add more load to it. That’s why it wakes up the alternator to produce more voltage
@OzMechanics I see, sry I'm mechanically inclined lol
I've been having this issue for a few years n can't get it figured out.. also my toyota doesn't have ac. It's a 98 camry.
The battery cable has a current sensor on it that tells the car ecu when to let the alternator charge
Where in the cable?
It's on the negative cable
@@sanjayjames1778 I've been doing this for 55 years I'm retired I've got an 05 Kia Rio I'm on my third alternator of course the postal system damaged it in shipment and I sent one back but I've had the same problem charging for a while works for a week or two and then quits and then it doesn't charge anymore so I was going to replace all of my cables and all of my ground straps but I don't see anything on any cable that looks like a sensor
The car i have is a 2016 kia rio
So what was the problem
There was no problem when I got the vehicle. The customer was worried that the vehicle was charging at 12v not aware that this vehicle has a smart charge alternator. I explained how the system works on the video. As on the first time he replaced the alternator I’m not too sure why it was replaced.
Great vid!! Oz is in SnapOn and Autel heaven. Nice place to b. Lol
Was pcm the issue?
No. If you carefully watch the entire video, you'll see Oz determines that this Hyundai AMS charging system is functioning normally.
ua-cam.com/video/bgyWB8OtfKM/v-deo.htmlsi=1C68tu7giN9KRmyQ
What did you unplug? you didnt say?
Before I removed the connector I was explaining on what I was going to do. And it was to disconnect the alternator connector
smart charge ,good video cheers
Is this whats called a variable speed alternator??
Years years ago on a 2003 expedition that's happen to me. Ended up with fusebox internal soldering was bad resoldering an boom fix it
Nice Troubleshooting there, Some folks don't understand System Description, lack of comprehension, They just shot-gun parts
It's the smart alternator design extra dumb they start out at regular voltage and then decrease when there's no load and even when you're driving it only will stay at the higher voltage for a little bit
My 83 Toyota 22r does this exact thing with an external voltage regulator?
Have you heard this occurring in 2008 Ford f150 4.2 L v6?
2008 don’t have smart charge alternator
I would say normal .. the voltage spikes on start to recharge the battery from taking the power out of the battery to start it Also the interior lights come on And the computer system reads cold starts etc
Good video, I actually learned something new today 😳
Thanks for watching
can a loose or faulty ground cable lessen the life of an alternator?
so what was the problem did you ever find out?
Did you watch the whole video ? It shows that there was never a problem
@@OzMechanics SO WHY DID HE KEEP PUTTING ALTERNATORS IN IT?
@@smokenbudesq because he kept on reading 12.6 volts. But that’s how the vehicle charges. It’s a smart charge system. Was there a part on the video you didn’t understand? Seeing if I can help out
@@OzMechanics OK SO IT WASN'T THE BATTERY LOSING POWER WHY EVEN BOTHER IDIOTIC . HE SHOULD HAVE RESEARCHED IT IN THE MANUAL.
SO OBVIOUSLY WASTED MY TIME AND YOUR TIME HOPE YOU CHARGED HIM.
@@smokenbudesq to be honest, some seasoned techs have been burned by these smart charge system. And I was one of them. I just got to focused on pats hat was infront of me and just kept on thinking, “ vehicles should be charging at 14V”. After that I make sure to read service info now to really understand the system I’m working on. Thanks for watching
So what was the issue?
Customer thought there was in issue because he saw 12.6 volts but the vehicle did that due to it being a smart charge system.
EXCELLENT I live by Allen genoa/Spencer near your shop.
Awesome. Hey that’s for watching
That's normal for a smart alternator to act this way so it doesn't put extra load on the engine if the battery is replenished.
Yes like explained in the video. We explained that in service information segment. Thanks for watching
Nice demonstration of an on-demand alternator. Makes sense, really. Why waste power unnecessarily?
Great video Oz, this is the 1st alternator video I've ever seen on UA-cam indicating ~ 12.4 Vdc at Idle. I believe most of the Alternator videos I've seen would have called this a Bad Alternator, do you know if a 2006 Toyota Tundra would operate like this Hyundai, i'm always monitoring the Alternator voltage and it seems Low ~ 12.6 to 12.4 at idle but when cruising and off idle voltage jumps up to 13.6 to 14.1. Thanks again for your video.
Before replacing any part, find out why it failed! Was it just age? Did it failed because of another part failing? Etc,etcetc.
Right here....have a beer every time he says it.....I dare you!