In this video we show a classic example of ground side voltage drop causing a no start on this 99 Chevy Tahoe. When you have more than one accessory that quits working all at the same time and a no start there is usually a common cause. A common power or a ground for example. Let's see what we find here. - Enjoy!
Follow up to this video, the repair:
Mastering Voltage Drop Testing with Pete Meier and "G" Jerry Truglia:
The Trainer #47: What measuring voltage on the ground side means:
If an SMA Video has helped you out please consider giving using "Patreon" to help support us. The videos take real time to create and pull us away from real work that pays our bills. CLICK HERE:
--Eric O.
If you don't like Patreon feel free to use the "PayPal Me" link:
The South Main Auto Amazon Store:
AES Wave Automotive Diagnostic Tools:
Simply send and E-mail to SMAstickers including: your shipping address and e-mail address in the text, I in turn will send you a Paypal invoice for $5 each USA or $6 each international. Let me know how many you want and as soon as the Paypal invoice is paid I will ship them out ASAP! Thanks for your support of our channel!!
--Eric & Vanessa O.
Feel like sending some swag to SMA because you love the videos but don't know where to send it?
Just ship it here:
South Main Auto Repair
47 S. Main St
PO Box 471
Avoca, NY 14809
Due to factors beyond the control of South Main Auto Repair, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. South Main Auto Repair assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. South Main Auto Repair recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of South Main Auto Repair, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not South Main Auto Repair

48 thoughts on “Chevy truck – no start, flickering lights gauges – voltage drop testing”
  1. Avataaar/Circle Created with python_avatars Kyle Turner says:

    Thank you for the video! My issue wasn't the exact same. I had a faulty main ground wire, but your troubleshooting with the Voltage Drop Testing let me figure that out. Thanks again!! And you did a great job with the video and explaining what was going on. Loved the non-formal feel of it.

  2. Avataaar/Circle Created with python_avatars Unknown Master says:

    Thanks for the vid I really enjoyed your content and gained a lot about voltage drop today so thank you just what I needed 💯

  3. Avataaar/Circle Created with python_avatars Victor Manuel Puerto Cruz says:

    Nice yob

  4. Avataaar/Circle Created with python_avatars Fred Glespie says:

    Will that ground strap causes your alternator not to charge

  5. Avataaar/Circle Created with python_avatars Samantha Spinale says:

    That's exactly what my 00 burban does and my ground is frayed just a little bit!

  6. Avataaar/Circle Created with python_avatars Jq foster says:

    Chevy Tahoe something totally wrong with it it needs fix’s and it’s to old that’s back in the 90s

  7. Avataaar/Circle Created with python_avatars Stan 808 says:

    Great video! Yes, Chevy trucks are notorious for bad grounds and I’d definitely know, being a lifetime Chevy man! You’d figure Chevy and GM engineers know better. No wonder, Gavin’s a Toyota fan!

  8. Avataaar/Circle Created with python_avatars Rae-Shon Wells says:

    I have a 95 Chevy Tahoe with this same exact issue. I’ve been to 5 different mechanics and none of them could figure what the issue was. Thanks for posting this. It’s a shame that I’ll have to go back to mechanic and make them watch your video.

  9. Avataaar/Circle Created with python_avatars ozzman530 says:

    I know this video is a few years old but this is a fantastic video on chasing elecctrical issues. Thank you for this detailed instruction.

  10. Avataaar/Circle Created with python_avatars ur done x says:

    if my car started doing that in the middle of the night or just in general i would be terrified 😂

  11. Avataaar/Circle Created with python_avatars kam shaft says:

    mine does that biut also the stick flickers like a humming bird

  12. Avataaar/Circle Created with python_avatars Sam Rugtiv says:

    Well done eric o.soak him good

  13. Avataaar/Circle Created with python_avatars Eno 91 says:

    I have question why my lail light is flashing?
    I did replace on my clacic gm based opel back light to new'r design that problem acured if I aply brakes light all 3 are flashing?
    I tought the wiering was wrong so I put old bulb holders back ON.
    And still that thing is flashing just on the back side the flashers to the front are ok tought.
    Am I missing somthing?
    Culd corosion build up do the same thing on the plug in's?
    Did the relay go bade ore the activator handel ?
    Its preaty much anoying acurance .
    Again I did put back on the original bulb holder back they are similar designs after all just bether looking light .
    I cant finde any thing wrong instead of corosion litel.
    Do those old bulb holders have neutral plating in them?

  14. Avataaar/Circle Created with python_avatars Doug says:

    Good find Eric, not a bad fix for a vehicle that has over a quarter of million miles on it.

  15. Avataaar/Circle Created with python_avatars Kurt King says:

    All vehicles In general are good its the owners and the way they do or dont maintain their vehicle is the reason that they are crap I personally love trucks and cars dodge chevy Toyota doesn't matter to me the name if you take care of your vehicle it will last a very very long time

  16. Avataaar/Circle Created with python_avatars 3wrapframe says:

    “Piece of Chevy”… that’s what we call them. For some reason though we keep buying them

  17. Avataaar/Circle Created with python_avatars Greg Huckeba says:

    Sounds like a typical Ford man takes 2 hours explain a 5-minute fix and charge for 4 hours but all these new vehicles with computers have ground problems One sensor can shut off 53 ridiculous

  18. Avataaar/Circle Created with python_avatars ed barrking says:

    Yeah you have helped me a lot doing these videos thanks. From Hou.Tex.

  19. Avataaar/Circle Created with python_avatars dnl machine says:

    "I probably could have been electrocuted".
    If you dont have at least 10 life experiences where that phrase applies, there is still much learning to be done.
    Great vid again Mr O.
    Stay gold.

  20. Avataaar/Circle Created with python_avatars Trey Slay says:

    I'm gonna try this on my 96 cause my gauges takes a minute to fully light up

  21. Avataaar/Circle Created with python_avatars Antonio Claudio Michael says:

    Crusty connection to engine from the body ground

  22. Avataaar/Circle Created with python_avatars Antonio Claudio Michael says:

    Good work on finding the voltage drop and the issue being a body ground Eric O @SouthMainAutoRepairLLC

  23. Avataaar/Circle Created with python_avatars j horton says:

    The boy looks like Mrs. O.
    I'm sure he'll be turning wrenches soon.
    Using a test light neg to neg for voltage drop. Truly inspired, I would never have thought of that but it makes perfect sense.

  24. Avataaar/Circle Created with python_avatars chili5555 says:

    Lol! “Ship it!”

  25. Avataaar/Circle Created with python_avatars Michael Real says:

    Nice mohawk/

  26. Avataaar/Circle Created with python_avatars John Cunnington says:

    It all clicked on why trailer lights that have a bad ground light up the other filament in the bulb to find a ground.

  27. Avataaar/Circle Created with python_avatars Brian Thompson says:


  28. Avataaar/Circle Created with python_avatars MrMaddparkison says:

    I've got a 96 an I know this vid is 3 years old but. I'm working of alternator 3 in a few days. I know they all can't be bad. I've replaced the grounds hell even add some. POS have been cleaned an checked. I went a grabbed a alt off a 5.3 with the 4 pin connector an all seems good. So do you think maybe it was just needing more amps or the factory 105 amp should have been good enough. It started with just voltage drop under load. Then to this.

  29. Avataaar/Circle Created with python_avatars Brian Hind says:

    Explanation of the voltage drop was correct. Eric, you do marvelous explanations for your viewers. Engineering level explanations need to stay with engineers. Evan is great help….is he for sale ? Thanks for all your videos, all lacking BS of any kind. Cheers!

  30. Avataaar/Circle Created with python_avatars Richie The Sailor says:

    Good visual evidence for better understanding.

  31. Avataaar/Circle Created with python_avatars twwtb says:

    Thumbs Up for sure. Saved me a lot of trouble if this happens out on the road. Now I know what tools, cables, connectors, etc to have with me.

  32. Avataaar/Circle Created with python_avatars michelediane miller says:

    eric,,,, how did you fix it? what did u use to fux it?

  33. Avataaar/Circle Created with python_avatars Papa’s Funny Farm says:

    Handsome boy has a BOSS haircut!

  34. Avataaar/Circle Created with python_avatars Alan Christensen says:

    I know I have watched this one before but always refreshing and fun to watch and see you! Being just you! Ah! 2018 video the good old days when we had so much more freedom of expression for free thought and thinking and now if you say something that disparages a brand watch out – worse if you say the wrong anything… Gee whatever happened to us? But as I said So glad to see you again! I am stunned anyone could give you a thumbs down you are one of the greatest problem-solvers who shares real live information for others to learn….

    Crazy problem called to help someone last night with a 2011 Chevy Equinox when they turned the key the dashboard went dark (instrument cluster) cant take out of park. Release the key lights come back on. Battery has 12.4V. It was dark and late and I did not really have my stuff with me…This was just a test and go thing…called a friend who happened to be in the area and he jumped in – I suspect a wiring issue? Ground? He is leaning toward a Ignition key failure? Why? We did remove bezel by shifter and pushed on interlock switch to move into Neutral and tried to start – same indications. I really think we lost a Ground… It was running so says customer who claims he parked it for a while came back out and then no crank no start… fairly new battery… Interesting they tried to jump the battery… The guy was telling me his cable end from his car running was HOT to the touch but the cable connected to the non-starting car were Cool… Hmmm! Sure sounds like if there was no ground end of course that end would be cool because energy was not being passed through it therefore…because it would require a proper ground would it not to enable the flow of electrons which would then cause heat …

  35. Avataaar/Circle Created with python_avatars Jeffrey Crossno says:

    Snow inside of any vehicle, especially in a Chevrolet may cause electrical inconsistency. Please continue. That's a good kid . Fortunate Dad !

  36. Avataaar/Circle Created with python_avatars PFS Enterprises, LLC Hill says:

    It's really refreshing to see someone including their family or children in their work. My father did the same thing and gave me a love for mechanics that continues to this day. I did the same with my children. Even my daughter has basic knowledge of what is wrong and how to fix it and she has. Always good to have knowledge. Keep up the good work you explain it in terms that are perfect to understand. God bless and good luck

  37. Avataaar/Circle Created with python_avatars Peter Williams says:

    F O R D fix or repair daily, found on rubbish dumps, FAST ON RACE DAYS as you can probably notice that I'm not a Ford fan GMH for me you have probably not heard of Holden but really like a vehicle called Holden Torana GTR XU1 192cu inline 6 producing 300hp plus. I don't know if you have ever seen or heard of the Bathurst 1000 the Torana GTR XU1 was driven by the great Peter Brock he won this race 9 times. Alan Moffitt was the Ford driver he drove a Ford GT HO Phase 3 at the time was the fastest 4 door sedan in the world got to see your teaching your son the proper way to do things

  38. Avataaar/Circle Created with python_avatars Josh Weiser says:

    Thank you for the help because I am working on my 98 suburban k2500 5.7l vortec and I have been having a issue with a hot ground on the battery when trying to crank

  39. Avataaar/Circle Created with python_avatars Gary K says:

    Worst thing you can hear is "sometimes"

  40. Avataaar/Circle Created with python_avatars Ted Cunningham says:

    Ty you guys explained it great. As always you saved me

  41. Avataaar/Circle Created with python_avatars John Dickerson says:

    I've owned 17 very reliable gm vehicles in my life. Now I'm driving a Tundra. "Adigatto"

  42. Avataaar/Circle Created with python_avatars jay frames says:

    Hey Eric great video man, thanks. Can a bad ground cause low voltage at the under hood fuse box to the ignition system only? I have a 06 chevy express 4.8l with 7.8v at the fuse box on ignition, engine 1, and engine 2 fuses?

  43. Avataaar/Circle Created with python_avatars Pastor George Middleton Jr says:

    Eric urgent answer needed please,
    Im driving my 03 sierra 5.3 and same issue we have tested upper grounds and all seem gine but then randomly it shuts down and will not start would you say it is still a lower ground that would cause this? Very similar issue to this Tahoe

  44. Avataaar/Circle Created with python_avatars John Bassett says:

    This explains the movie where the 55 Chevy car is said to be possessed by it's original owner and starts and drives itself killing other's that killed it's owner , mystery solved !!!

  45. Avataaar/Circle Created with python_avatars 95turbostang says:

    I think you explained it perfectly you had ground going down towards the engine block but not making a good connection basically. 🤘👍