I am a novice mechanic. I worked in the business in the 90,s. I am humbled by your knowledge. I now work in the high voltage industrial field. Thanks, I learn everyday.
ive been working on cars for years and eletrical has always been a hardspot for me. espically in understanding it.. but they way you just presented that was awesome and very easy to understand thank u keep on the good works and teaching brother
I resemble that remark. Lol I just recalled in the Apollo 13 movie, how they systematically tested each electrical item and circuit to achieve a specific voltage. Kinda crazy.
My jumper cables have never let me down on the ground test. They're 20 ft long, solid copper, 2 ga. that I paid 70 bucks for over 25 years ago. Just checked, they've only increased in price by $100.00 or so. Funny story, found a bad engine ground by accident. Was testing no start on old big car LTD with a fender mounted solenoid.Customer had replaced solenoid 3 times, so I'm test lighting it with test light to bat gd and happened to lay test light on engine. IT LIT UP., Sometimes IT'S OK TO BE LUCKY RATHER THAN GOOD.
About 30 years ago, a man came into my shop and asked to borrow my jumper cables like the kind you’re talking about.and I told him specifically that they were very expensive cables to make sure to bring them back. He understood clearly so he never brought them back.sad😢
Why can't a fella connect his handy dandy test light to the positive terminal of the battery and touch the engine with the pointed end of the test light to see if it lights up thus letting you know if it's grounded or not? If it lights up it's gounded. If it doesn't its not. That's always been the way I roll...
Thanks for teaching me something new this morning. In the mid west, those grounding straps become chicken noodless in just few years. Specially GM trucks
i replaced the head gasket on a Sentra i bought really cheap. the final moment, i hopped in the drivers seat and turned the ignition. the car cranked but did not start. After a few more cranks. i took out a spark plug and it was completely dry, no gas smell either coming from the cylinder. I checked for a spark, no spark. later that night......oh yeah the grounding strap that attaches to the back of the manifold....went out the next morning and connected......the car started right up 👍👍👍👍
This is the best video I’ve come across diagnosing bad grounds, and Ive never had this issue before on anything. I was never shown for situations like this. Been Fighting with a 2008 Impreza. Cleaned the engine to body ground after replacing a cooked battery, cleaned the terminals, and started up, no cels. Came back hours later to show my friend, and it wad All crank no start. All the cels. Either the MAF sensor, the pig tail, the wire from the MAF to the comp, or the corroded negative terminal is to blame (super ugly looking but no build up and not cracked). I’ll go back and check the grounds and batt posts later on, wish me luck!
I am currently looking at a potential ground cable issue from my battery to the motor, to the frame, the ground strap you did and checking the positive cable connection to my 2010 tahoe fuse panel. These are notorious for bad cable corrosion inside the jacket. My vehicle is doing crazy stuff on the dash with guages, nav drops out, locks up down, poor power, etc. Seats wouldn't move, you name it. And I must say, I've been a industrial electrician for over 30 years working with 480 down to 24 volt controls and I simply didn't think to apply the voltage drop method across the metal frame / motor like you did for that situation and with the test light, not just a meter. I find automotive wiring to be a field of its own, with all its own set of quirks. I'm going to get the test light I thought I would never need, because of the quick visual you displayed which my digital multimeter simply might not catch! Absolutely great troubleshooting information!!! 👍🏻
Replace engine ground strap and make a new ground wire point to the wire harness on the passenger side of that engine should be installed. Computer ground & engine ground is the issue.
@@jlrockafellaIt wasn't a ground issue after all, and ended up being the vehicle suspension module was rotted out and shorting out my CANBUS network. As soon as I removed the suspension module and connected the network end resistor it has work fine.
I have used all these methods. And I’ve also incorporated the jump box method. I go out to a car it’s got a slow crank or no crank I hook the jump box up to the jump points still no crank or slow crank I move the negative to the engine block car cranks pretty much confirms it for me.
When you connect them to the jump points is it still on the battery as well or do you take the battery out of the equation? I have a slow crank randomly with a brand new battery not even two weeks old and it will randomly crank slow or even spin the starter then engage finally. I wanna see if I have a bad ground.
@@grahambumpas3213 I have the battery connected as well. Did you replace the starter for a Slow Crank? The best way to check though honestly, especially if you’re only one person is a multi meter with a min max function.
Absolutely the best ground related video on youtube and/or the internet. Very thourough and informative! Thank you for your knowledge. Priceless!!! I've just confirmed that I've had a ground issue from day one of no start no crank. I purchased a new stsrter and after avoit 20 starts it had a no crank no start. I then replaced the starter thinking that it was a faulty starter and low and behold after about 5 starts I get a no crank no start issue again. I quickly assume that the starter is faulty and that the after market aeket company is sellimg me a faulty starter...however, I jacked.the car up to inspect the ground strap and it broke off into 2 pieces!!! I replaced the strap and got crank and start. After about 3 starts I got another no stsrt no crank and again i stsrted thinking about the starter being faulty...However, I opened up the car and got to the stsrter and did tests again...oh and I g Forgot to mention, the starter they sent me initially works when I did a bench test outside the car with a charged battery!!! So I do the same bench test with the second stsrter and it is working fine! I cleaned the engine where the starter connects with a wire brush for a nice clean contact point for a good ground connection to the starter...the car started!!! Then after about 5 starts the car again had a no start no crank!!!! I did the jumper cable method by connectimg nother ends to the valve cover side of rhe ground by the passenger side under the hood and low and behold it started again!!! Point of my madness and trauma is that I never knew these fuckimg ground wires/straps could be such assholes and pains in my ass!!! Please check ALL THE GROUND STRAPS grounding the engine. FML.
@@SuperMarioDiagnosticscan you please help me ive been playing up the butt and no one can fix my car 2011 Chevy Malibu 3.6 engine staryer replaced alternator replaced twice battery replaced twice and today i was stuck on the road for 5 hours, no family small town and the jerk who said he fixed my car would not answer my calls ended up walking with my special needs son i dont understand ive paid so many people to fix my car amd still its not starting ugh no ones honest anymore van you please look up where a bad ground would be im lost there no where else to bring my car small town life sucks! Ive been on UA-cam looking and cant find anything the lights go high then low then i die out all 3 parts are good that i mentioned helppp
This is funny. almost 50 yrs ago that was my first diag and i didnt find it. a ford tech stopped by station n 2mins ltr told me what it was. Sweet video.
There is a 4th method, if you’re using a jump-pack/booster then connect it to the engine ground instead of chassis ground. Although it’s pretty similar to the jump lead method where the quality will play a part.
Very educational video, this was a very nice test to do for confirming the ground issue on SAAB 9-3TDi, (that often suffers from bad grounds from engine to chassie). Thanks for another great video.
A friend had a Cadillac that was running terrible with all kinds of electric issues. He was about to sell it not running right. We got on the phone. His wife was working the key. I had him ground the engine with jumper cables. I could hear it smooth out over the phone! A new ground cable had it running fine.
GREAT VIDEO! These tests should be done on most diags to eliminate a bad ground as an issue. I have hooked up both ends of 20' 2 gauge jumpers to note any increase in performance but the test light test is goig to be a quick test i will be doing on a daily basis to eliminate bad ground from my list of possibilities.
In modern gasoline spark ignited vehicle applications, there are several circuits that use the engine block ground as a return path back to the source (conventional current), with the source being; the alternator (when the vehicle is running) or the battery (Key on ignition off, starting and sleep current). In reference to this video, the focus is on the engine block ground, however, in actuality we are interested in the complete circuit path, that is, supply from and return to the power source. In regards to maintaining older vehicles, we find that corrosion degrades electrical connection integrity, with the failures normally occurring in places where the copper cable strands are crimped to a lug or eyelet but the strands are not sealed and exposed to the elements (especially bad in the USA salt belt states). For example, you could have a Battery POS top post lug crimped from the factory with a folding cable crimp, where in the same space allowed, could have used a barrel style Battery POS lug and done a hex or circular hydraulic crimp. In both cases, dual wall heat shrink could be use to help seal the connection. But many times what you find from the factory is a folded crimp without any heat shrink. Basically, bare copper strands and lug ears crimped, open and exposed to the elements. In reality, we are interested in checking proper operation of the overall circuit integrity and not just one connection in the circuit like the block ground. However, the block ground gets the focus because it usually fails first due to corrosion, but not always. You could have a battery lug fail first, but this is usually easier to diagnose if the battery is located under hood where you can easily inspect the health of the lugs and posts. The tests for voltage drop at high current are really just an indirect way to measure connection resistance (assuming the cables are undamaged). Mario does have access to a Pico scope, so he could actually use a current clamp and voltage input to measure the complete circuit resistance for a specific test. Like starting or charging. If we look at the starting circuit, we have the battery (source) and the starter (load) in the circuit, as well as all the cable and connections. So, you could measure the current with the current clamp from the battery, while at the same time, measuring the battery voltage at the battery posts. From this you could use a Pico math channel to calculate resistance V/I in real-time. But, with this advanced test what is a good dynamic resistance value? What is good and what is bad and by how much. Well, you would have to measure some known good working vehicles and get some base values to compare it to. This dynamic resistance test is attractive though when you have easy access to the circuit source (battery), for testing the overall circuit, which will include the block ground. You just clamp on the current clamp, attach the voltage channel alligator clips to the battery, and start the vehicle, then review the waveforms and math channel calculation all time aligned.
This video I needed a year ago when my sisters ground strap rotted away. This car had issues starting in the cold for years and then in the middle of summer It just quit. When my mechanic gave me the strap I pulled it apart in my hands, the whole thing was green inside and out worse then the strap you have in this video. I tried to get the car going as it wasn’t home. One thing I thought of doing but forgot to try while I was there was the jumper cable for an alternate engine ground. I’m glad you showed that it doesn’t work 100% because I thought if I remembered to try that it would have worked and have a tow and several hours.
Very informal save me lots of money and time the whole time I had a bad ground on my 2013 BMW X5 550I change the starter twice still no crank after seeing your video try the jumper cable method start it right up thanks thumbs up👍😁
2008 Saturn Sky Redline. Ive been chasing a P0300 "Misfire code" (all 4 cylinders) for about a month now. I tried all of the basic things like plugs and even swapped out all 4 coil packs with no luck. I tried a few things recently that have fixed it but im not 100% positive which one it was as i did 3 things all at the same time. 1)I did half a dozen full throttle runs for about 30 seconds. 2) closed gap to .025" on my plugs (were .035"). 3) made a homemade battery to motor to frame cable. I couldn't get a CEL afterwards and its been a few hundred miles since doing the above, so im pretty sure one of those did the trick. Recently an online forums friend shared a Technical Service Bulletin about these vehicles having a bad ground on the motors and called for reestablishing a better ground due to this exact same problem. I think its safe to say that I probably got lucky with making my own engine ground and will probably have my local dealership do the TSB next time its in there for its state inspection.
The jumper cable would have burnt me because I woukd figure they would be better than have the ground straps I see that function. Gives me the motivation to make a shorter high quality set. Thanks my man , good video !
not all bad wiring looks as bad as that ground strap, on my hyundai elantra the ground strap was effectively broken, you couldnt tell visually, and voltage drop testing seemed to pass, until you had multiple accessories working and the car was warm. electrical problems are sneaky, so thats the benefit of the jumper cable, it will let you see bad wiring eve if they look just fine visually. cheers bro thanks for the upload
I've been a tech for 30 years and have seen a lot of young school trained kids come and go , these basic testing skills are either not taught or emphasize well in school. Its not sexy like BMW or Mercedes training so I'm sure it has less impact than basic theory and testing that can be applied to every make and model.
I would venture to say that more than half of working techs use inadequate testing when it comes to starter motor diagnosis. Something repetitive like that should taught as a standard algorithm, a check list method that avoids skipping steps. Done correctly it takes less than 5 minutes with basic tools, provided the posts on the starter are accessible. Rather than focusing on too much theory, students need a rapid cookbook approach that avoids shortcut disaster.
I just bought a Cadillac DTS... for $800 because it had a bad engine ground... the owner and mechanics, it took me a while to figure it out, I had those issues on Jaguars all the time.... so as soon as I purchased one, I installed extra engine block grounds...
Thanks for the video. Here's how I conceive the bad ground: the high resistance at the bad ground causes the voltage potential (under load) at the engine block to be higher than that at the battery ground causing the testlight to light when connected from battery ground to engine block. This is basically the same as you explained on the paper.
I AM NOT THE SHARPEST PENCIL IN THE BOX , BUT I THINK THAT MEANS YOUR ENGINE IS PROPERLY GROUNDED .... ALMOST THE SAME AS IF YOUR TEST LIGHT WAS ON B+ AND THE NEGATIVE BATTERY POST ......
@@abramturley2572 If it is bright the engine is properly grounded. If you connect the test lamp directly to the alternator housing you know the alternator and the engine both have good ground connection.
@@gregscheyd4131 Yes, bright light on the test lamp is what it means. Also if you connect a test lamp directly to the alternator housing you know the alternator and the engine both have good ground connection.
Had an 11 volt drop on the positive battery cable to a starter on a 2020 ram 2500 the other day. I cleaned the connection at the starter and still had about a 500mv drop.. I chalked it up to probably being about normal since it was a 6.4L and the truck started every time after.
BMW say max allowed voltage drop in a circuit is 300mV and 500mV for staring and charging circuits but I think that’s for the entire circuit so + to + AND - to -, personally my go to is the multi-meter method. The only time I really use my test light is to check powers and grounds when I can’t back-prob or find a breakout lead.
Great video! Hope you can help on this issue. Is not a car engine fault but probably you recognize the problem: A few days ago, while riding my scooter SYM VS 125, a lot of smoke started coming out of the front of the bike and the engine started to fail. I turned off the ignition and cut the battery current. At home I took it apart to see what was going on and the rectifier was visibly burnt. I took the bike to a workshop where they changed the rectifier and the battery, but they didn't solve the problem. The new rectifier continues to heat up a lot and too fast, as if something is short circuiting. As they couldn't solve the problem and it still cost me a few €€, I picked up the motorcycle with the fault. Tests i have done: - the battery is new and has 13.1V before the starter - with the three yellow wires from the stator connected to the rectifier, the bike works fine at low revs, fails at medium and the rectifier heats up uncontrollably; with these wires disconnected from the rectifier, the bike works well at any speed, but as we know, the battery is not charged - at idle the 3 yellow wires measure about 40V from stator - the resistant test on stator show equal values on three wires; no ground conductivity; no open circuit on each coil - apparently all the masses are well connected. Any idea what it could be causing this recurrent failure of the rectifier? Note: traditional G6Y carburetor engine with electronic rectifier and CDI, year 2010.
Question -- instead of making all these tests to the ground on the fender of this BMW, can you connect your tests directly to the negative battery post instead? I assume the only reason he has to use the ground by the fender is because this BMW has the battery in the trunk. Not like most cars that have the battery under the hood. Can someone please confirm. Thanks Mario for making this video. Great info!
Thanks for posting this up. I just measured from ground post to positive wire and got 12.3V. From positive wire to oil filter housing also 12.3V. Does this rule out my ground strap? On my 2008 528, I just started to have intermittent longer cranking start issues. At one point I did notice that my break pedal did not depress all the way down prior to cranking. Very strange. Thanks again.
Mario had a similar situation but with the customer over my shoulder looking, but what I used was my TOP DON . Was on twin engine crane first went to the cables ends for pony motor connected top don and did battery test failed , next followed 43 feet of battery cables found a master cut off switch connected top don both sides with of the post and TOP DON found high resistance on the B side . Less than 40 min and permanent fix completed Sooo this issue was going on for weeks new starter new batteries and it was intermittent problem but with the TOPDON. Saying FAIL. The customer did not challenge the road call fee and repair bill and THANKS to TOPDON we gained a new customer
thanks for the info. i have the same problem. at first i suspected the issue was with starter. took off starter and bench tested it worked fine, and installed it back in. i contacted negative jumper cable from ground stud to engine block and tried to crank and got at least slow crank. should i be getting voltage reading on multimeter from positive post to engine block? Thanks 🙏
Mario would your thermal infrared camera show the high resistance across that engine ground strap when cranking? Probably not as well as the test light or the VOM.
Guys the home handyman carries the cheap jumper cables around in his car which helps when you are in trouble but a technician should be carrying a set of jumpers that he feels proud to have in his arsenal. Have a good set specially made up that lasts a life time and more. I did.
Will a bad grounding strap cause a alternator to fail. I have replaced the alternator twice and each starts with 14 volts, After a minute they stopped charging.2000 BMW 323i, Thanks
A battery jumper cable from engine block to frame doesn't necessarily mean a bad jumper cable. Could be that the starter frame is not making a good contact with frame ground (high resistance ) giving you a slow or no crank. Clean all cable and starter connections. And yes check engine block to frame ground strap connection and for corrosion.😮
Hi. I have a 2013 Hyundai Sonata 4-cyl that has good battery and new/good stater but nothing happens when key button is pushed. Nothing will power up except the button's little dim light as I'm pushing it. Any ideas where to start? Thanks!
Great channel! If I have multiple available module calibration file updates ( IPC, ABS, BCM etc) does the sequence I update them in make a difference? Thank you much.
Hi there I now this is a weird question to ask but wood it mark a battery go flat all the time if it’s not grounded I’ve gone through tow batteries so far
Hi sir, Look at signs of My BMW X5 E70 2006 as follows, is that the probalty of Poor ground cable, right??? - poor starter, hesitant pulling starter. - the fob key is hard to received or hark to take it out - loss Voltage due to the Ground index is too high upon starter? The new battery used only 1,5 year is gone to dead - ebox fan: sometimes is flickering, sometimes show fauld ebox fan code - acceleration at 40km/hour signs a little hestitating due to ECU not enough ground cable signal to operate well - the headlight on the driver’ s side sometimes doesn't light up Wainting for your commence. Tks
My 2014 Ford Transit Connect the starter just makes a little sound then stops battery is fully charged when the starter makes a sound the engine does not crank. Previously, the van was running then it stopped moving forward I revved the engine numerous times trying to get out of traffic went through the gears the van would not move I then cut it off and now it will not crank.
I am a novice mechanic. I worked in the business in the 90,s. I am humbled by your knowledge. I now work in the high voltage industrial field. Thanks, I learn everyday.
I made the same career change lol
so its common for you to encounter 3 phase
ive been working on cars for years and eletrical has always been a hardspot for me. espically in understanding it.. but they way you just presented that was awesome and very easy to understand thank u keep on the good works and teaching brother
I resemble that remark. Lol
I just recalled in the Apollo 13 movie, how they systematically tested each electrical item and circuit to achieve a specific voltage.
Kinda crazy.
My jumper cables have never let me down on the ground test. They're 20 ft long, solid copper, 2 ga. that I paid 70 bucks for over 25 years ago. Just checked, they've only increased in price by $100.00 or so. Funny story, found a bad engine ground by accident. Was testing no start on old big car LTD with a fender mounted solenoid.Customer had replaced solenoid 3 times, so I'm test lighting it with test light to bat gd and happened to lay test light on engine. IT LIT UP., Sometimes IT'S OK TO BE LUCKY RATHER THAN GOOD.
Yeah the modern ones are made of chinesium (copper glad aluminum wire). Total garbage. You are smart to hold onto those 100% copper jumpers
About 30 years ago, a man came into my shop and asked to borrow my jumper cables like the kind you’re talking about.and I told him specifically that they were very expensive cables to make sure to bring them back. He understood clearly so he never brought them back.sad😢
Why can't a fella connect his handy dandy test light to the positive terminal of the battery and touch the engine with the pointed end of the test light to see if it lights up thus letting you know if it's grounded or not? If it lights up it's gounded. If it doesn't its not. That's always been the way I roll...
Because even one strand of a bad ground strap will light up that test light but won’t start the car.
@SuperMarioDiagnostics gotcha
Great teaching. Would love to hear more about electrical diagnostics.
Thank you.
Thanks for teaching me something new this morning. In the mid west, those grounding straps become chicken noodless in just few years.
Specially GM trucks
i replaced the head gasket on a Sentra i bought really cheap. the final moment, i hopped in the drivers seat and turned the ignition. the car cranked but did not start. After a few more cranks. i took out a spark plug and it was completely dry, no gas smell either coming from the cylinder. I checked for a spark, no spark. later that night......oh yeah the grounding strap that attaches to the back of the manifold....went out the next morning and connected......the car started right up 👍👍👍👍
Explained very simple for everyone one to understand. Keep up the good work.
It's a joy to watch your thorough, simplistic explanation of your diagnosis of problems. Keep them coming.
This is the best video I’ve come across diagnosing bad grounds, and Ive never had this issue before on anything. I was never shown for situations like this. Been Fighting with a 2008 Impreza. Cleaned the engine to body ground after replacing a cooked battery, cleaned the terminals, and started up, no cels. Came back hours later to show my friend, and it wad All crank no start. All the cels. Either the MAF sensor, the pig tail, the wire from the MAF to the comp, or the corroded negative terminal is to blame (super ugly looking but no build up and not cracked). I’ll go back and check the grounds and batt posts later on, wish me luck!
Good of you to share your knowledge and we appreciate the work u put into the videos
I am currently looking at a potential ground cable issue from my battery to the motor, to the frame, the ground strap you did and checking the positive cable connection to my 2010 tahoe fuse panel. These are notorious for bad cable corrosion inside the jacket. My vehicle is doing crazy stuff on the dash with guages, nav drops out, locks up down, poor power, etc. Seats wouldn't move, you name it.
And I must say, I've been a industrial electrician for over 30 years working with 480 down to 24 volt controls and I simply didn't think to apply the voltage drop method across the metal frame / motor like you did for that situation and with the test light, not just a meter. I find automotive wiring to be a field of its own, with all its own set of quirks. I'm going to get the test light I thought I would never need, because of the quick visual you displayed which my digital multimeter simply might not catch!
Absolutely great troubleshooting information!!! 👍🏻
Replace engine ground strap and make a new ground wire point to the wire harness on the passenger side of that engine should be installed. Computer ground & engine ground is the issue.
@@jlrockafellaIt wasn't a ground issue after all, and ended up being the vehicle suspension module was rotted out and shorting out my CANBUS network. As soon as I removed the suspension module and connected the network end resistor it has work fine.
I have used all these methods. And I’ve also incorporated the jump box method. I go out to a car it’s got a slow crank or no crank I hook the jump box up to the jump points still no crank or slow crank I move the negative to the engine block car cranks pretty much confirms it for me.
When you connect them to the jump points is it still on the battery as well or do you take the battery out of the equation?
I have a slow crank randomly with a brand new battery not even two weeks old and it will randomly crank slow or even spin the starter then engage finally.
I wanna see if I have a bad ground.
@@grahambumpas3213 I have the battery connected as well. Did you replace the starter for a Slow Crank? The best way to check though honestly, especially if you’re only one person is a multi meter with a min max function.
@@jwoeltje6949 haven’t replaced the starter yet wanna see if it could be bad ground.
The min max function what would that tell me?
@@grahambumpas3213 if you have resistance on the wire or a bad ground
Your going to do a voltage drop test.
@@jwoeltje6949 thanks for your time! I appreciate it
Absolutely the best ground related video on youtube and/or the internet. Very thourough and informative! Thank you for your knowledge. Priceless!!! I've just confirmed that I've had a ground issue from day one of no start no crank. I purchased a new stsrter and after avoit 20 starts it had a no crank no start. I then replaced the starter thinking that it was a faulty starter and low and behold after about 5 starts I get a no crank no start issue again. I quickly assume that the starter is faulty and that the after market aeket company is sellimg me a faulty starter...however, I jacked.the car up to inspect the ground strap and it broke off into 2 pieces!!! I replaced the strap and got crank and start. After about 3 starts I got another no stsrt no crank and again i stsrted thinking about the starter being faulty...However, I opened up the car and got to the stsrter and did tests again...oh and I g
Forgot to mention, the starter they sent me initially works when I did a bench test outside the car with a charged battery!!! So I do the same bench test with the second stsrter and it is working fine! I cleaned the engine where the starter connects with a wire brush for a nice clean contact point for a good ground connection to the starter...the car started!!! Then after about 5 starts the car again had a no start no crank!!!! I did the jumper cable method by connectimg nother ends to the valve cover side of rhe ground by the passenger side under the hood and low and behold it started again!!! Point of my madness and trauma is that I never knew these fuckimg ground wires/straps could be such assholes and pains in my ass!!! Please check ALL THE GROUND STRAPS grounding the engine. FML.
on cheap jumper cables test you can always use both cables providing ground (red and black parallel ) lol good work
Wow that’s an obvious but needed bit of info for the next time I do this! Funny I never thought of this!
I actually did this too, to no avail
Good one.
@@SuperMarioDiagnosticscan you please help me ive been playing up the butt and no one can fix my car 2011 Chevy Malibu 3.6 engine staryer replaced alternator replaced twice battery replaced twice and today i was stuck on the road for 5 hours, no family small town and the jerk who said he fixed my car would not answer my calls ended up walking with my special needs son i dont understand ive paid so many people to fix my car amd still its not starting ugh no ones honest anymore van you please look up where a bad ground would be im lost there no where else to bring my car small town life sucks! Ive been on UA-cam looking and cant find anything the lights go high then low then i die out all 3 parts are good that i mentioned helppp
Really good information Mario! Thank you for sharing brother!
This is great....we can NEVER get enough examples of testing methods....AWESOME STUFF!!!!
Thanks for this video. Great info! Found many bad grounds with jumper cables!
This is funny. almost 50 yrs ago that was my first diag and i didnt find it. a ford tech stopped by station n 2mins ltr told me what it was. Sweet video.
Thanks to your videos I learned alot about electrical on my vehicle thank you🎉 got that same ground light works wonders 🎉
There is a 4th method, if you’re using a jump-pack/booster then connect it to the engine ground instead of chassis ground. Although it’s pretty similar to the jump lead method where the quality will play a part.
A VERY LOGICAL SIMPLYFIED EXPAINATION DIRECT TO THE POINT. WELL, PRESENTED. THANK YOU, MARIO,
Honestly - you are wonderful and your explanation of the problem was easy and uncomplicated. Thank you
Very educational video, this was a very nice test to do for confirming the ground issue on SAAB 9-3TDi, (that often suffers from bad grounds from engine to chassie). Thanks for another great video.
A friend had a Cadillac that was running terrible with all kinds of electric issues. He was about to sell it not running right. We got on the phone. His wife was working the key. I had him ground the engine with jumper cables. I could hear it smooth out over the phone! A new ground cable had it running fine.
Very nice quick field reference.
Great explanation and ways to check. This is the best video ive seen explaining a easy but definite way to understand a huge problem.
Great stuff. Thanks for sharing it!
Thanks for watching!
Liked it 👍🏼👍🏼 . Thanks for sharing your knowledge !
I enjoyed your stuff , its easy flowing and very easy to grasp.
GREAT VIDEO! These tests should be done on most diags to eliminate a bad ground as an issue. I have hooked up both ends of 20' 2 gauge jumpers to note any increase in performance but the test light test is goig to be a quick test i will be doing on a daily basis to eliminate bad ground from my list of possibilities.
In modern gasoline spark ignited vehicle applications, there are several circuits that use the engine block ground as a return path back to the source (conventional current), with the source being; the alternator (when the vehicle is running) or the battery (Key on ignition off, starting and sleep current). In reference to this video, the focus is on the engine block ground, however, in actuality we are interested in the complete circuit path, that is, supply from and return to the power source.
In regards to maintaining older vehicles, we find that corrosion degrades electrical connection integrity, with the failures normally occurring in places where the copper cable strands are crimped to a lug or eyelet but the strands are not sealed and exposed to the elements (especially bad in the USA salt belt states).
For example, you could have a Battery POS top post lug crimped from the factory with a folding cable crimp, where in the same space allowed, could have used a barrel style Battery POS lug and done a hex or circular hydraulic crimp. In both cases, dual wall heat shrink could be use to help seal the connection. But many times what you find from the factory is a folded crimp without any heat shrink. Basically, bare copper strands and lug ears crimped, open and exposed to the elements.
In reality, we are interested in checking proper operation of the overall circuit integrity and not just one connection in the circuit like the block ground. However, the block ground gets the focus because it usually fails first due to corrosion, but not always. You could have a battery lug fail first, but this is usually easier to diagnose if the battery is located under hood where you can easily inspect the health of the lugs and posts.
The tests for voltage drop at high current are really just an indirect way to measure connection resistance (assuming the cables are undamaged). Mario does have access to a Pico scope, so he could actually use a current clamp and voltage input to measure the complete circuit resistance for a specific test. Like starting or charging. If we look at the starting circuit, we have the battery (source) and the starter (load) in the circuit, as well as all the cable and connections. So, you could measure the current with the current clamp from the battery, while at the same time, measuring the battery voltage at the battery posts. From this you could use a Pico math channel to calculate resistance V/I in real-time.
But, with this advanced test what is a good dynamic resistance value? What is good and what is bad and by how much. Well, you would have to measure some known good working vehicles and get some base values to compare it to. This dynamic resistance test is attractive though when you have easy access to the circuit source (battery), for testing the overall circuit, which will include the block ground. You just clamp on the current clamp, attach the voltage channel alligator clips to the battery, and start the vehicle, then review the waveforms and math channel calculation all time aligned.
Good dynamic resistance value=0 ohms.
AS Usual... Outstanding!!! Thank you! Super Mario! You have A Way of Teaching, that is SO Easy to understand! 2 Thumbs UP, Liked and Subscribed!
This video I needed a year ago when my sisters ground strap rotted away. This car had issues starting in the cold for years and then in the middle of summer It just quit. When my mechanic gave me the strap I pulled it apart in my hands, the whole thing was green inside and out worse then the strap you have in this video. I tried to get the car going as it wasn’t home. One thing I thought of doing but forgot to try while I was there was the jumper cable for an alternate engine ground. I’m glad you showed that it doesn’t work 100% because I thought if I remembered to try that it would have worked and have a tow and several hours.
Great info! WHERE DID YOU GET THAT DUNDER MIFFLIN NOTEPAD! That's hilarious 😂
I was with the wife at the mall and she went into a store called box lunch. And there it was
something everyone needs to know. thanks.
Very informal save me lots of money and time the whole time I had a bad ground on my 2013 BMW X5 550I change the starter twice still no crank after seeing your video try the jumper cable method start it right up thanks thumbs up👍😁
2008 Saturn Sky Redline. Ive been chasing a P0300 "Misfire code" (all 4 cylinders) for about a month now. I tried all of the basic things like plugs and even swapped out all 4 coil packs with no luck. I tried a few things recently that have fixed it but im not 100% positive which one it was as i did 3 things all at the same time.
1)I did half a dozen full throttle runs for about 30 seconds.
2) closed gap to .025" on my plugs (were .035").
3) made a homemade battery to motor to frame cable.
I couldn't get a CEL afterwards and its been a few hundred miles since doing the above, so im pretty sure one of those did the trick.
Recently an online forums friend shared a Technical Service Bulletin about these vehicles having a bad ground on the motors and called for reestablishing a better ground due to this exact same problem. I think its safe to say that I probably got lucky with making my own engine ground and will probably have my local dealership do the TSB next time its in there for its state inspection.
Excellent explanations! You just got a new sub!
As always, great thanks Mario
Great video as always, thanks for sharing!
The jumper cable would have burnt me because I woukd figure they would be better than have the ground straps I see that function. Gives me the motivation to make a shorter high quality set. Thanks my man , good video !
not all bad wiring looks as bad as that ground strap, on my hyundai elantra the ground strap was effectively broken, you couldnt tell visually, and voltage drop testing seemed to pass, until you had multiple accessories working and the car was warm. electrical problems are sneaky, so thats the benefit of the jumper cable, it will let you see bad wiring eve if they look just fine visually. cheers bro thanks for the upload
I've been a tech for 30 years and have seen a lot of young school trained kids come and go , these basic testing skills are either not taught or emphasize well in school. Its not sexy like BMW or Mercedes training so I'm sure it has less impact than basic theory and testing that can be applied to every make and model.
I would venture to say that more than half of working techs use inadequate testing when it comes to starter motor diagnosis. Something repetitive like that should taught as a standard algorithm, a check list method that avoids skipping steps. Done correctly it takes less than 5 minutes with basic tools, provided the posts on the starter are accessible. Rather than focusing on too much theory, students need a rapid cookbook approach that avoids shortcut disaster.
I just bought a Cadillac DTS... for $800 because it had a bad engine ground... the owner and mechanics, it took me a while to figure it out, I had those issues on Jaguars all the time.... so as soon as I purchased one, I installed extra engine block grounds...
Thanks for the video.
Here's how I conceive the bad ground: the high resistance at the bad ground causes the voltage potential (under load) at the engine block to be higher than that at the battery ground causing the testlight to light when connected from battery ground to engine block. This is basically the same as you explained on the paper.
🤔
@@gussingh3948 Are you undecided? I wrote that so someone can correct me if I happen to be wrong.
thanks for the video grounds are so important these days on cars
What about as a first test to connect a test lamp from B+ to the engine and watch for if it lights up, how dim it is or not lit at all?
I wonder what that would have done probably dim to no light like you said. Bit if it was bright what would that mean
I AM NOT THE SHARPEST PENCIL IN THE BOX , BUT I THINK THAT MEANS YOUR ENGINE IS PROPERLY GROUNDED .... ALMOST THE SAME AS IF YOUR TEST LIGHT WAS ON B+ AND THE NEGATIVE BATTERY POST ......
@@abramturley2572 If it is bright the engine is properly grounded. If you connect the test lamp directly to the alternator housing you know the alternator and the engine both have good ground connection.
@@gregscheyd4131 Yes, bright light on the test lamp is what it means. Also if you connect a test lamp directly to the alternator housing you know the alternator and the engine both have good ground connection.
Had an 11 volt drop on the positive battery cable to a starter on a 2020 ram 2500 the other day. I cleaned the connection at the starter and still had about a 500mv drop.. I chalked it up to probably being about normal since it was a 6.4L and the truck started every time after.
Thanks for the video. Very impressed.
BMW say max allowed voltage drop in a circuit is 300mV and 500mV for staring and charging circuits but I think that’s for the entire circuit so + to + AND - to -, personally my go to is the multi-meter method. The only time I really use my test light is to check powers and grounds when I can’t back-prob or find a breakout lead.
Good information and explanation.
Thank you Mario your explanation is simple and right. You are super
Excellent how to test video, thanks.
Another great video…thanks!
Great video very well done thx so much
Excellent tutorial Mario. Thanks!
Really good information here!
THANKS!!
Great video!
Hope you can help on this issue. Is not a car engine fault but probably you recognize the problem:
A few days ago, while riding my scooter SYM VS 125, a lot of smoke started coming out of the front of the bike and the engine started to fail. I turned off the ignition and cut the battery current.
At home I took it apart to see what was going on and the rectifier was visibly burnt. I took the bike to a workshop where they changed the rectifier and the battery, but they didn't solve the problem. The new rectifier continues to heat up a lot and too fast, as if something is short circuiting. As they couldn't solve the problem and it still cost me a few €€, I picked up the motorcycle with the fault.
Tests i have done:
- the battery is new and has 13.1V before the starter
- with the three yellow wires from the stator connected to the rectifier, the bike works fine at low revs, fails at medium and the rectifier heats up uncontrollably; with these wires disconnected from the rectifier, the bike works well at any speed, but as we know, the battery is not charged
- at idle the 3 yellow wires measure about 40V from stator
- the resistant test on stator show equal values on three wires; no ground conductivity; no open circuit on each coil
- apparently all the masses are well connected.
Any idea what it could be causing this recurrent failure of the rectifier?
Note: traditional G6Y carburetor engine with electronic rectifier and CDI, year 2010.
Question -- instead of making all these tests to the ground on the fender of this BMW, can you connect your tests directly to the negative battery post instead? I assume the only reason he has to use the ground by the fender is because this BMW has the battery in the trunk. Not like most cars that have the battery under the hood. Can someone please confirm. Thanks Mario for making this video. Great info!
Thank you for your thorough explanation it will help me alot!!
Thanks for posting this up. I just measured from ground post to positive wire and got 12.3V. From positive wire to oil filter housing also 12.3V. Does this rule out my ground strap? On my 2008 528, I just started to have intermittent longer cranking start issues. At one point I did notice that my break pedal did not depress all the way down prior to cranking. Very strange. Thanks again.
Excellent video well explained thanks ! 🙏🏻😉👍🏻
I always prefer the voltage drop method 👍!!
Nice clear video, subscribed now
Mario had a similar situation but with the customer over my shoulder looking, but what I used was my TOP DON . Was on twin engine crane first went to the cables ends for pony motor connected top don and did battery test failed , next followed 43 feet of battery cables found a master cut off switch connected top don both sides with of the post and TOP DON found high resistance on the B side . Less than 40 min and permanent fix completed Sooo this issue was going on for weeks new starter new batteries and it was intermittent problem but with the TOPDON. Saying FAIL. The customer did not challenge the road call fee and repair bill and THANKS to TOPDON we gained a new customer
Thank you for your knowledge and video's USA 🇺🇸
I like that you get right to the point without too much unnecessary verbiage. How did that ground strap get so bad in FL??
Salt in the air maybe ?? I know cars near the sea are the worst. Retired/transplanted Yankee maybe ??
Thanks for the refresher/reminder. ck,wisc.
thanks for the info. i have the same problem. at first i suspected the issue was with starter. took off starter and bench tested it worked fine, and installed it back in. i contacted negative jumper cable from ground stud to engine block and tried to crank and got at least slow crank. should i be getting voltage reading on multimeter from positive post to engine block? Thanks 🙏
Valuable info yet again. Thank you. I am just curious as to what forced you to check for engine ground.
Probable he is seen before and the light test is easy to do. GM trucks hate the salt too!
Probably poor / no crank
Yes been there before. Always a good test to rule out early
@@SuperMarioDiagnostics Sure,.....I will keep that in mind.
Mario would your thermal infrared camera show the high resistance across that engine ground strap when cranking? Probably not as well as the test light or the VOM.
I should have said those are stock Buick rods. Love your channel!
👍 thanks for sharing my friend!
THANKS MARIO ,,, GREAT VIDEO !!!!!!!!!!!
Muchas gracias, me va a servir mucho de aprendizaje.
Thanks for the video. Great tip
Love your test light! Is it something available for us to buy or is this custom?
You seem to know your stuff my man. Thanks.
Guys the home handyman carries the cheap jumper cables around in his car which helps when you are in trouble but a technician should be carrying a set of jumpers that he feels proud to have in his arsenal. Have a good set specially made up that lasts a life time and more. I did.
Good vid, very educational.
More solid advice, Mario, you da' man!
Will a bad grounding strap cause a alternator to fail. I have replaced the alternator twice and each starts with 14 volts, After a minute they stopped charging.2000 BMW 323i, Thanks
A battery jumper cable from engine block to frame doesn't necessarily mean a bad jumper cable. Could be that the starter frame is not making a good contact with frame ground (high resistance ) giving you a slow or no crank. Clean all cable and starter connections. And yes check engine block to frame ground strap connection and for corrosion.😮
Thank you for the video.
Cool information,
Why the test light does not act as jumper cable? And light bulb get blown!
Excellent!!
When you write about load on a Dunder Mifflen note pad, I feel compelled to say, “That’s what she said”.
“Load”
Great Job once again Mr Mario. question where did you get the testlight from?
Cornwell
@@SuperMarioDiagnostics Thanks for the quick response! I’ve learned alot from you an I can’t thank you enough 👊🏻
Hi. I have a 2013 Hyundai Sonata 4-cyl that has good battery and new/good stater but nothing happens when key button is pushed.
Nothing will power up except the button's little dim light as I'm pushing it.
Any ideas where to start? Thanks!
Great channel! If I have multiple available module calibration file updates ( IPC, ABS, BCM etc) does the sequence I update them in make a difference? Thank you much.
Depends on vehicle, some yes, some no
Thanks for you informative video
Great explanation 👍
Thanx bro.Scanner Danner and Super Mario my favourite 2 youtube channels😉
NOT A BAD MIX AT ALL !!!!!!!
Hi there I now this is a weird question to ask but wood it mark a battery go flat all the time if it’s not grounded I’ve gone through tow batteries so far
Nice explanation i just subscribed
Hi sir,
Look at signs of My BMW X5 E70 2006 as follows, is that the probalty of Poor ground cable, right???
- poor starter, hesitant pulling starter.
- the fob key is hard to received or hark to take it out
- loss Voltage due to the Ground index is too high upon starter? The new battery used only 1,5 year is gone to dead
- ebox fan: sometimes is flickering, sometimes show fauld ebox fan code
- acceleration at 40km/hour signs a little hestitating due to ECU not enough ground cable signal to operate well
- the headlight on the driver’ s side sometimes doesn't light up
Wainting for your commence. Tks
Dope ! Thank you sir. 🫡
Love your videos brother.
My 2014 Ford Transit Connect the starter just makes a little sound then stops battery is fully charged when the starter makes a sound the engine does not crank. Previously, the van was running then it stopped moving forward I revved the engine numerous times trying to get out of traffic went through the gears the van would not move I then cut it off and now it will not crank.