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.

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 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.

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

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 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.

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

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.

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 👍👍👍👍

on cheap jumper cables test you can always use both cables providing ground (red and black parallel ) lol good work

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!!! 👍🏻

Thanks to your videos I learned alot about electrical on my vehicle thank you🎉 got that same ground light works wonders 🎉

This is great....we can NEVER get enough examples of testing methods....AWESOME STUFF!!!!

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.

Really good information Mario! Thank you for sharing brother!

Really good information here! THANKS!!

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.

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.

Honestly - you are wonderful and your explanation of the problem was easy and uncomplicated. Thank you

something everyone needs to know. thanks.

Thanks for this video. Great info! Found many bad grounds with jumper cables!

A VERY LOGICAL SIMPLYFIED EXPAINATION DIRECT TO THE POINT. WELL, PRESENTED. THANK YOU, MARIO,

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!

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 !

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 enjoyed your stuff , its easy flowing and very easy to grasp.

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

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.

Very nice quick field reference.

You seem to know your stuff my man. 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👍😁

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...

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

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!

Liked it 👍🏼👍🏼 . Thanks for sharing your knowledge !

As always, great thanks Mario

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.

Great video as always, thanks for sharing!

I always prefer the voltage drop method 👍!!

thanks for the video grounds are so important these days on cars

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 Mario your explanation is simple and right. You are super

Great info! WHERE DID YOU GET THAT DUNDER MIFFLIN NOTEPAD! That's hilarious 😂

Good information and explanation.

I should have said those are stock Buick rods. Love your channel!

Excellent tutorial Mario. Thanks!

Thank you for your thorough explanation it will help me alot!!

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.

When you write about load on a Dunder Mifflen note pad, I feel compelled to say, “That’s what she said”.

Another great video…thanks!

Excellent how to test video, 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.

Excellent video well explained thanks ! 🙏🏻😉👍🏻

👍 thanks for sharing my friend!

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?

Thanks for the refresher/reminder. ck,wisc.

More solid advice, Mario, you da' man!

Thank you for your knowledge and video's USA 🇺🇸

THANKS MARIO ,,, GREAT VIDEO !!!!!!!!!!!

Good video 👍

Nice clear video, subscribed now

2:12 the man even uses a good quality pen.

Dope ! Thank you sir. 🫡

Love your videos brother.

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!

Great explanation 👍

Good vid, very educational.

Great video man

Thanks for the video. Great tip

I’m a DIYer and I have never seen the test like example before thank you very much

Thanx bro.Scanner Danner and Super Mario my favourite 2 youtube channels😉

Thank you for the video.

I like that you get right to the point without too much unnecessary verbiage. How did that ground strap get so bad in FL??

That is why I trashed all those cheapo jumper cables and keep a solid copper thick gauge one.

In all my years or decades better said have never seen the test light method, makes since...

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.

Valuable info yet again. Thank you. I am just curious as to what forced you to check for engine ground.

Thank you

Thanks for you informative video

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.

Biggest 👍many thanks

Good job 👍

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.

Muchas gracias, me va a servir mucho de aprendizaje.

Great info

New subscriber!!🔥🔥🔥

wow very interesting 👍

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 🙏

Nice explanation i just subscribed

Thanks Mario.

Awesome

Its the same principal of reading voltage drop across a fuse. Just much higher current… and the ground wire became the fuse…

Nice job..

Good Morning everyone.

My problem im having is voltage drop once the car starts to warms up, brand new battery and brand new alternator, previous battery tested good, replaced the alternator with a reman at first, because the orignal failed a test, some how finagled fhe parts store to get me a new Duralast gold, and still having voltage drop after it wams up. Its a Honda, alternator control and Eld have been disabled through a tunning aoftware. Next is grounds and wiring at the harness side of things. Cars starting to piss me off. Belt tension is tight at the alternator.

Thank you!