Intermittent symptoms are a mechanics worst nightmare. There is an old say, "you can't fix it if it isn't broke." I don't know who said it but I assume it is an old wise mechanic. 95% of the time I will not take on intermittents because they end up being time wasters and I prove it to myself yet again....
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97 thoughts on “The car i couldn’t fix…”
  1. Avataaar/Circle Created with python_avatars Jim Bob says:

    Gm garbage

  2. Avataaar/Circle Created with python_avatars Vincent Sullivan says:

    Hi Eric; Yes, intermittent are a PAIN! As I see it there are 2 aspects to this one. The first aspect is which of the 3 circuits is causing the problem. The suggestion of using 3 fuses is a good one to localise which circuit has the problem. Better would be to use 3 amp clamps. The second aspect is what is happening at the exact time the fuse blows. The fuse (or fuses) can blow and the owner may not notice at the time and only becomes aware of the problem when he gets stopped by the police. By then, there is no correlation to what was happening exactly when the fuse blew. Years ago I was confronted with a similar intermittent problem, though it was not automotive. Being an electronics engineer I designed a little box that would monitor several channels of voltage and current. The current and voltage levels where the box would indicate an error were adjustable and if the voltage or current went above or below the set limits (this is called a "window comparator") it would light an LED for that channel which would stay on until the box was reset with a push button. It also had a beeper to let the machine operator know exactly when the error condition occurred so he could correlate the moment of error to what the machine was doing. In the automotive context this would be things like going over a bump, going through the car wash, opening a door, moving a steering column, opening the tailgate, etc…

    So in this case you put the box on the passenger seat or some other convenient place in the passenger compartment with the box power leads connected to always hot power and ground. You then adjust the box to only indicate an error if the current significantly exceeds expected values for the 3 circuits involved and clamp the 3 amp clamps to the three circuits. The car will have wires all over the place but that is the price you have to pay. If you have enough channels in the box you can even measure at several points in the same circuit to try and localize the site of the fault. Tell the customer to drive it and if the box starts beeping he should note exactly what was happening at the time and then bring the car back to you in a reasonable time for further diagnosis. This isn't going to fix the problem for you but it should give you much better direction as to where the problem is.

    I am retired now and the box stayed with the company but it was a pretty simple design using some op-amp ICs and a bit of digital logic. Even at today's prices for electronic parts a basic version could be built for a few tens of dollars not counting the cost of the amp clamps. I hope this stimulates some additional ideas on how to tackle this PITA Yukon.

  3. Avataaar/Circle Created with python_avatars Infinite Velocity says:

    is that an aftermarket overhead video screen?

  4. Avataaar/Circle Created with python_avatars bob smith says:

    Time to get Pine Hollow involved.

  5. Avataaar/Circle Created with python_avatars Boris The German says:

    Trailer connector. The plug itself. Just some things I’ve seen.. hope this helps that guy out..

  6. Avataaar/Circle Created with python_avatars Jared Kennedy says:

    Man I hate intermittent issues. That's why I like working on the same three of four basic vehicles, then you get used to them. I had one where a Ford F59 chassis started blowing the left front turn signal fuse intermittently. I'd replace the fuse, check the harness for chafing, replaced the front LED turn signal assemblies, it'd go out and be back in a day or two. So, I'd do more testing, pull harness clips out, open up suspect areas of the harness, shake it, test drive, no issues. It'd be back just the same. Well, I had been pulling the relays to jumper the connector and test the system out with constant power, and one time gave the relay a little shake, and heard a rattle. I opened it up to find the NC contact (unused in this application) had broken free and had burn marks where it had shorted between the coil ground and relay output pins. New heavier duty relay, and no more issues.

  7. Avataaar/Circle Created with python_avatars Robert Hackenberg says:

    Might need to replace that fuse holder box, they go high resistance sometimes.

  8. Avataaar/Circle Created with python_avatars Fred Carlson says:

    When you're just the mechanic and they gave you the job to do I didn't have a choice to fix it I've told service adviser it takes time and money to find that kind on intermetant problem customer choice with no warranty on finding it

  9. Avataaar/Circle Created with python_avatars Benjamin Baugh says:

    It would be bad if it's related to the turn signals and the steering wheel turning, the customer just hasn't noticed it and the turn signals weren't used during this diagnosis.

  10. Avataaar/Circle Created with python_avatars D Jelonek says:

    Not saying it's right, but if it works…. is it wrong?
    On the fleet equipment I used to work on, I'd make us a short harness with a (fuse size) circuit breaker and 30+ amp fuse (double the OEM fuse ratting). Plug that in and let it roll. The breaker ensured the circuit would work, the fuse ensured no fires. Eventually, the arcing was evident…. even after the "whisker" has long since melted off.
    Never had an issue doing this, except perhaps a bit of overheated loom, but…disclaimer…. try at own risk.

  11. Avataaar/Circle Created with python_avatars New Jersey Bill says:

    As they say in the old country, you can't fix what ain't broke!! 🙂

  12. Avataaar/Circle Created with python_avatars Z Ack says:

    Watch i bet its some lamp socket that has an exposed hot and when a working bulb is put in it shorts out and blows the bulb same time it pops the fuse.. so you literally couldnt find the issue unless replace the blown bulbs.. lol

  13. Avataaar/Circle Created with python_avatars Gordon says:

    Intermittents are always a pain. I had one many years ago when my wife and I purchased a Plymouth from the in-laws that they had poured a lot of money into for a charging system that just would not work properly. It had received multiple alternators and batteries but never was solved. Apparently the gods were with me the day I tried to find the problem because, after much time spent verifying that the alternator was working properly, I just happened to see a little wisp of smoke inside the ammeter and discovered that it had a high resistance at the mounting stud. A quick trip to the auto recyclers got me a replacement and the problem was cured.

  14. Avataaar/Circle Created with python_avatars Patrick Lee says:

    Eric, VERY common issue in these damned suburbans, the wiring harness coming out of the lift gate into the headliner rubs through all of the damned time. GM refuses to acknowledge the issue and won't post a bulletin on it.

  15. Avataaar/Circle Created with python_avatars Mike R says:

    At that point I'm thinking one of the bulbs might be intermittently shorting internally. I've seen it before on an 1157.

  16. Avataaar/Circle Created with python_avatars Dan Bentch says:

    Great vid! Glad to hear that Toby the 10 pound shop cricket is still alive and well! 😉

  17. Avataaar/Circle Created with python_avatars Lloyd Tucker says:

    Wait for it to be reliably faulty

  18. Avataaar/Circle Created with python_avatars Matty says:

    I give you a lot of credit Eric for your patience. 1st red flag "6 months to blow fuse" 2nd red flag "would like to pick it up Saturday",, ahhh nooo. we dont run a non-profit repair shop. we need to put food on the table. can't believe anyone would criticize your effort. i do have an idea is maybe a tech school may look at it. they can afford the time to learn perhaps. TY for the videos.

  19. Avataaar/Circle Created with python_avatars Chip Burns says:

    The customer told you how to recreate the problem. He said to install the new harness he provided which he said immediately pops the fuse.

  20. Avataaar/Circle Created with python_avatars Chip Burns says:

    The radio harness also has a parking light circuit for the dimmer. I have blown my headlight fuse messing with the switch once.

  21. Avataaar/Circle Created with python_avatars Chip Burns says:

    Wow! Im un-subbing 😂😂😂

  22. Avataaar/Circle Created with python_avatars J.R. Glancy says:

    My 99 Ram 1500 would intermittently blow the fuse for the taillights. Usually after a heavy rain and only after hitting a bump; no amount of jiggling harnesses could duplicate the problem. After a year of carrying around extra relays I found the problem…spare tire would slide a bit, after water traveled above it after a heavy rain, wearing out the harness above it.

  23. Avataaar/Circle Created with python_avatars Robert Anderson says:

    IF the customer really wanted the intermitent short fixed you could install 3 differant temperary inline smaller fuses on the output of each of the light circuits coming out of the fuse box. Then give it back to them and let them drive it.That way when one of the fuses blows you are that closer in pinpointing the location of the short by seeing whitch fuse blows .

  24. Avataaar/Circle Created with python_avatars Ivan Olsen says:

    did you check the fuse box itself … for crusties

  25. Avataaar/Circle Created with python_avatars Thomas Laub says:

    Im maintenance electrician in a steel mill the calls of it only happens sometimes are the worst. Usually end up making it look like you work on it for about ten minutes then tell them to call back when it breaks cause nothing is harder to find than a problem that doesn't exist currently. I did however have an issue like this with my superduty turn signal and it ended up being the steering column shaft rubbed a harness under the dash took me months to stumble upon that issue.

  26. Avataaar/Circle Created with python_avatars Jesse Rocha says:

    I just finished fixing the same exact identical issue to my mother's 2001 GMC Sierra 1500. Fuse kept blowing on the left side front and rear marker and turn signal lights. After days of looking, I noticed the fuse would blow whenever I slammed the driver's door. I found a wire had chaffed and shorted on a metal guard/plate under the steering column. My mother's truck has a column turn signal lever. The shorted wire was from the turn signal lever running/chaffing on the edge of the metal guard/plate underneath where the column meets the dashboard. I suggest looking there!

  27. Avataaar/Circle Created with python_avatars MirceaD28 says:

    A problem might be that some light bulbs are at different W. The one with higher W are going to last but they draw much. I might say a bunch of stupid things

  28. Avataaar/Circle Created with python_avatars Melvin Jones says:

    How about the grounds . Small wires and cheep wires.

  29. Avataaar/Circle Created with python_avatars Muppet Gump says:

    Need to change your sign outside, unless Napa finally is sponsoring

  30. Avataaar/Circle Created with python_avatars Randy Mack says:

    Any shade tree mechanic knows how to fix this, keep putting in the next higher amp fuse until it quits blowing fuses. (Or melts/ burns up the whole harness) Although I'm not sure it's the recommended method!

  31. Avataaar/Circle Created with python_avatars Space Cadet says:

    Experience taught me early on as an electronic repairman, I do not attempt to repair an intermittent problem that is currently working okay. You can't fix what's not broke unless it's visually obvious.
    Customers don't want to hear this but most understand after an explanation.

  32. Avataaar/Circle Created with python_avatars Anyon Matt says:

    OMG please take some carb spray and kill that damn cricket in your shop!!

  33. Avataaar/Circle Created with python_avatars J B says:

    How is time wasted if you charge a diagnostic fee?

  34. Avataaar/Circle Created with python_avatars John Emberton says:

    I hope you're charging that cricket rent.

  35. Avataaar/Circle Created with python_avatars Kyle Matteson says:

    Could the tailgate lift cylinder be causing some flex or pressure on the tail lamp assembly or harness causing the short?

  36. Avataaar/Circle Created with python_avatars tac c says:

    The sad part is.. you didnt find it this time or do it this time..IE "If I can do it, you can do it…?? " you blaming a hair wire for your misdiagnoses is shameful at best!.

    More over, to admit you cannot diagnose an intermittent issue is your explanation?! seriously?.. Your channel is tracking down electrical issues.. . and now its beyond your explanation !? Give me and your followers a F'n break!

    Maybe the issue is a poor fuse connection.. or more importantly, its a poor repairman excuse to not want to find the problem.??

    so disappointed!

    Intermittent issues are the future of problems… Im sorry, you lost me on this episode.

    What you should have said.. " If I cant do it.. maybe you can do it … "

  37. Avataaar/Circle Created with python_avatars Jeff Freeman says:


  38. Avataaar/Circle Created with python_avatars MBS Brakes Mobile Mechanic says:

    crickets back……

  39. Avataaar/Circle Created with python_avatars TheElectronMan says:

    I had 1985 Cutlass that went through like 5 alternators could not figure it out then one day after I replaced yet another alternator I was standing there and leaned over put my hands on the top of the front body panel and heard the idle drop and could tell the alternator was pulling massive current got to looking more closely and the main charge wire had gotten pinched between the two body panels I loosened a bolt pulled the wire out you could see it had been pinched just enough to where there was some insulation missing causing a sporadic short. Had I not know where to look I would have never found it. Small piece of tape to cover the now exposed wire and car never had another problem with the alternator again.. Point being had I not just leaned on the right part who knows when that would have been found it was pure luck I finally found it..

  40. Avataaar/Circle Created with python_avatars Jason Lyle says:

    I had a similar issue. I think it was the dimmer on the instrument panel lights. It was a roller resistor but sometimes went short. Chased it for a while.

  41. Avataaar/Circle Created with python_avatars Cammer68 Oliver says:

    I hear you bud! The majority of problems resulting in anything a man has made usually stems back to electrical. I’ve learned that in aviation Tech school. It’s hard to find the problem sometimes. A friend of mine has an early 2000s Ford expedition, passenger low beam has got no power coming to that harness. Somebody’s been in there monkeying around before, the wire is dead. So the only thing I can do for her is trace that wire all the way back and find that there’s a break in it somewhere. Poor lady has to drive around with her highbeams on! Lol. Nothing new, everybody does that these days anyway, bunch of morons. But I’m gonna trace that wire and find it for her. Definitely don’t want to jump off the driver side low beam to feed the passenger side. That’s not the right way to do it. Electrical issues are simply just a pain anyway sometimes. I like making my own custom harnesses for my old hot rod mustang but when factory stuff goes bad it’s a nightmare!

  42. Avataaar/Circle Created with python_avatars Rob Mut says:

    In this case your closing line should be: “If I can’t fix it, you can’t fix it”. LOL

  43. Avataaar/Circle Created with python_avatars Swallow Inn says:

    Hello Eric I feel your pain and your customers disappointment. Hard to fi d a problem when it is playing g hide and seek. Great real life video.

  44. Avataaar/Circle Created with python_avatars Medic Four says:

    I thought customer wrote that the new harness installed causes instant blown fuse. So he put the intermittent faulty harness back in. Maybe it would have made it a current fault….and easy fix. But I'm Just an Ambulance Driver