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Chevy S10 - GMC S15 and Sonoma Electrical Problems



  • gonogogonogo Posts: 879
    I looked up splice pack SP400.

    (CKT 1324, CKT 2509, CKT 2609) Tail lamp harness, on the center inside of the rear crossmember
  • ttsnowttsnow Posts: 1
    I own a 2004 chevrolet S-10 truck. Since early winter of this year I started having minor electrical issues. Interior lights not shutting off, alarm going off in the middle of the night, radio and speaker problems the cruise control stopped working. Then one day as my girlfriend was pulling out of her fathers driveway the drivers side air bag suddenly deployed in her face. Thank God it didn't happen a minute later. As an accident no doubt would have occurred. Possibly a fatal one. GM inspected the vehicle and informed me that the wire harness that runs directly under the drivers feet had been damaged resulting in the electrical problems and airbag deployment. This they (GM) claims was a result of enviromental factors (driver getting in the vehicle with snow on their feet.) Then they said there was nothing they could do about it. And I should take it up with my insurance company. The repair cost for this would be approx $2500. And ther is no after market wire harness and the damaged wire would just be spliced.

    A month after my incident a person with a 2004 tahoe had there vehicle burst into flames outside a store approximately 30 miles from where I live. GM also claimed enviromental factors in this incident. I guess we will just have to wait until one or more persons are killed because of these enviromental electrical incidents before GM admits that their wire harness location is the real probelm.

    So if you are in the market for a lightduty truck think twice about the Chevrolet and GM lines of vehicles.
  • tjf5tjf5 Posts: 1
    Did you ever figure this out? Mine is doing the same thing. Please help!
  • I have a 2004 Chevy S-10 with some of the same problems, horn sounding in the middle of the night etc. The problem first happen when the vehicle was new and the GM dealership said that they had fixed it. Now 7 years later it has reappeared.. I also have other problems. Please post any additional information on this problem. Thanks
  • dhearndhearn Posts: 1
    Just wandering if this problem got fixed. My 95 S10 pickup just started doing the same. It was intermitten for about 3 days now it is constant. I changed the alternator(which was still under warranty) but is still doing the same thing. Every time I turn the switch on the #4 fuse blows and the system quits charging, dash instruments quit, motor starts running rough and the transmission starts acting crazy.
  • 2003 GMC Sonoma - Both odometer and auto shift indicator lights (LED) inop. All other electrical components appear to be working. Lights went out for about a week and then came back on for several days, then they went out again. I purchased a Haynes manual but schematics are vague or non-existent. I am almost sure there is a connection issue "somewhere" but not sure where to start looking without schematic.

    Any recommendations on where to start looking or where to get complete set of wiring schematics?

  • Hello there. I am a new member to the site and I own a 99' GMC Sonoma. I have extensive working knowledge of GM's absolutely substandard wiring, parts and customer service so I will help you as much as I can. The advice I am giving should help many of you who have posted questions so here we go. My 01' Astro and my 99' Sonoma are both showing signs of extensive electrical issues and because of this I have done extensive research and troubleshooting as to prevent further damage and catostrophic failure such as airbags deploying and fires. YOU NEED TO KNOW THAT ALL WIRING IN LATE MODEL VEHICLES IS SUBSTANDARD AND VERY DANGEROUS ALL DONE TO SAVE COMPANIES MONEY...IT IS NOT JUST GM. We have our governing agencies to thank for the lax requirements. The new standard for automotive wiring is to place 2-4 copper strands in each wire instead of the "old fashioned" bundle and these will fail. The only way to remedy this is to spend the extra money for a HIGH QUALITY aftermarket harness and devote 20-30 hours of labor changing it all out (should you decide to do this, I recommend boxing up the original wires and fed-exing it to your local transportation authorities with a pleasant thank you card for their hard work). However there are common faults in GM's that could help you save time and money.

    1.) Instrument clusters on 94' and later vehicles are CRAP! You cannot repair nor service them with "resistor kits or any of that nonsense so dont waste your time. If you decide to replace it choose a nice aftermarket one that you like (will usually be cheaper than OE part and you will not be condoning the manufacturers original incompetance) but also remember you are required to have the new onw "mapped" as to set the odometer to the mileage of your current one.

    2.) IGNITION SWITCH FAILURE and/or bad ground. Start your engine then wiggle your key and switch will be surprised how many issued this will cause if it crackling or cutting out, lights acting up, guages acting up, engine running rough and/or dying, and so on and so forth.

    3.) Fuse box (engine and under dash) as described above these horrible wires break continuity but APPEAR fine. You must use and ohm meter to check for breaks in the wire from start to finish (dont forget to contort the wire and watch meter for variations)

    4.) Bad chassis to engine ground straps. CHECK THEM ALL ! ! ! ! Again, substandard materials that corrode and fail because they SUCK

    ****BE SURE TO BE CAREFULE OF ALL YELLOW CONNECTORS ! These are part of the SRS system and can cause airbags to deploy if tampered with. If you absolutely must mess with these DISCONNECT THE BATTERY ! It usually will cause injury if deployed and can cause DEATH.****

    Bottom line is that I am a GM guy but will be the first to tell you that the ENTIRE automotive industry is using substandard practices while building our vehicles but they are not entirely to blame. It should be illegal for these common but critical issues to be ignored and passed on to us to repair and recall campaigns should be issued. Maybe if enough of us contact our local and federal agencies enough to be a thorn in their side we will see something happen. I am ready, so lets do it. Feel free to email me with any specific questions. BE SAFE and good luck. GOD Bless.

  • I have a 2002 v6 auto s10.
    The issue started where the gauges other than the oil pressure and volt would drop off and the transmission (auto) would then be stuck in third gear even after the gauges would shoot back on. The problem got worse over a year (gauges dropping off more often and transmission stuck in third). Six codes pulled up that ECM/trans sensors. I just had a new ECM installed. Now the gauges show up until I actually start the engine, then they drop off immeditately with a jump on for a second ever so often and trans is stuck in third. I have been able to manually shift to 2nd starting off from a stop and then manually shifting to third in order to keep from killing the transmision. Unable to manually go into first or forth and no gauges makes for a interesting drive. Any ideas. I don't want to just start replacing transmission sensors in hopes for solving the issue.
    Side note: before replacing the ECM "sometimes" the gauges stayed on and the transmission worked perfectly. The day I dropped it off to have ECM put in a 10 minute trip it ran perfectly no issues start from house to shop (of course) but knew it was there so had them do the ECM anyway hoping to resolve issue.
    It took the shop 4 tries to get ECM to pass security set up to allow engine to run.

    Does this sound like a poor ground, wire short, bad ignition column cylinder, or trans sensor or other? I have seen others with this issue on the net but have not seen a direct answer for 2002 s10 v6 automatic.

    Engine has never skipped a beat during all this nonsense.

    A VERY BIG THANKS in advance.
  • Here is another blogger that I found with the same issues.

    03-15-2009, 09:02 PM
    I have a 2003 s-10 truck, and I have been having many problems with this truck. Right now i get SERVICE CODES P0758, P0740, P0753, P0785, and i have replaced the TCC solenoid and the wiring harness, i have also replaced both a and b solenoids. and still had the codes showing. I was told to try the ignition switch harnes, and that also did not fix my problems. I have no gauges,(only alt, and oil pressure), and it feels like i am stuck in 2nd gear, and there seems to be no power to go at all. Could it be my computer needs to be flashed or maybe a relay i don't know about? Please Help. Thanx
  • gonogogonogo Posts: 879
    Not sure what he meant by ignition switch harness. The ignition switch will cause this problem, the electrical one, not key.
  • A Big Thanks. I will give it a shot.
  • s10atiouss10atious Posts: 1
    edited October 2011
    i've got a '96 2.2l 5spd. and everything , i mean everything works down to the lighter, courtesy light and all bulbs in between. i guess i'm the lucky one :shades:
  • gonogogonogo Posts: 879
    My 99 2.2 auto does too.
  • hamerdownhamerdown Posts: 1
    edited October 2011
    i left the key on overnight and had a dead battery, i put the charger on it without disconnecting batt., then started it, with charger still hooked up, i think i killed my alternator, when truck is running, and i take the neg. batt. cable off it shuts down. battery light is on, guages failed, i needed a new batt. anyway, so i bought one, the guages work, 4 now, i drove to work, but left it there, so i didnt have to drive home at night using lights. seems like alt., but i would hate to buy and install, and find out its a brain, or wire harness, or something. any advice is appreciated. chevy s10 2000
  • kngjmzkngjmz Posts: 2
    First, NEVER, ever connect a battery charger to a automobile with battery cables connected as the amperage from charger is much different thatn that of the charging system. You said that while truck is running you disconn the neg. cable and it the same thing but disconnect the pos. Does it die? Do you have a voltmeter? If you do, start the truck and check voltage at the battery (black lead to neg. cable, red to positive) Your charging system should be putting out 13.8-14.5 volts. If it is not, replace the alternator. Also, most parts stores will test your alternator for free....simply remove the alternator and they will put it in a carbo load tester with a "pass/fail" result. This does sound like an alternator issue. If it where a harness or computer you would get a check engine light and other systems of the truck would not work. Feel free to email me should you need furher assistance.
  • After reading your post I realize that I am not the only one with this exact problem. When you spoke about the watching the volt guage float from 14 I literally had "deajavue" of driving in my 98' Sonoma. Since it has been over 4 years since your last post I am wondering if you found your problem and if so...WHAT WAS THE PROBLEM!?!? Please help! Thanks! :confuse:
  • Hello there. I see that I am by no means the only person that has major electrical problems with my 98' GMC Sonoma 5 speed. Tonight, I just replaced my 3rd battery in the past 1 1/2 years...luckily I purchased a battery with 3 year replacement for FREE! Anyways, this is what my truck does to annoy me...

    Sometimes it will drive fine all day, but others it barely wants to get a mile and the volt guage will fluctuate after staying pinned at 14 it will "float" a bit below 14 and if I use my blinker or some other electric instrument it goes down as well. Another thing it does is when I am driving the guages will all of a sudden go crazy...the MPH and RPM guage will go way high and then go all the way down. The other guages will act eratic as well and then the truck will shut off. Sometimes it will start right back up, but other times I will have to pull over and pray that it will start again. Tonight it didn't start at all...wouldn't jump-start either so I returned my battery for a new one, replaced it, and then proceeded to drive about 8 miles to my house without a single issue except I noticed the volt meter dip a bit when I used my blinker.

    I've had my starter replaced, and the battery and alternator have been checked and all check out fine. I've been told it could be a speed sensor, but the AAMCO told me that manual transmissions don't have a speed sensor?! The fuel pump has been recently replaced as well, but because it was shot. I see that many people have electrical problems with this vehicle and was hoping that you could give me a bit of advice on where to go next. Thanks! :confuse:
  • My 96 S-10 2.2 5 speed runs great with 300,000 miles but lately has been loosing all electrical power. It stalls and goes completely black. even the presets on the radio are erased. Turn the key nothing, no interior or exterior lights nothing. A few minutes later it runs fine again. I think this has happened while driving but the momentum just restarted the motor. I had battery checked and replaced two days ago. Alternator replaced a year a go.
  • the_big_althe_big_al Posts: 1,079
    first thing to check with electrical problem (especially in these trucks it seems) is a bad ground. Probably a main ground somewhere.
  • i have a 1999 chevy s-10 with a 2.2. When i have the car running and no lights on, the day time running lights do not come on. When i turn the lights on no head lights come on. Just the running lights. If i play with the column and put it in drive i can get the running lights on. Anyone have any suggestions???
  • tjacoby4,

    Did you ever figure this out?! This just happened to me recently. Any advice would be much appreciated.
  • when i am having issues i get nothing, not even the dome light. however, if i turn the ignition, my gagues will start to rise or flicker. I have to disconnect the battery then reconnect and everything will come back on and it will start. as i am driving, i can hear the alternator in the speakers and the dask lights flicker. i have replaced the ignition switch and alternator. thinkg short someplace or a switch. it has gradually got worse. today i had to jump it bypassing the battery. Any ideas?
  • If I had to guess, I'd say you have a bad ground. A major one, like the cable to the block, or the block to the frame, etc. Next time it happens, try just jerking on the cables and see if it comes back on. I just had this happen with my 79 Chevy truck. I turned on the headlights, which barely glowed, and started pulling on cables. When the lights came alive, I new where the problem was. It turned out to be where the negative cable went into the cable-end attached to the battery (Autozone junk).
  • Thanks for the idea, i was leaning toward that too. 160K and never changed cables. The 2 positive cables are wraped together and then break apart and go their own way. was thinking of the ground or that the 2 cables were arcing. won't be able to get to it until Friday but will let you know what i find out.
  • My son is having the same headlight issue with his 95 S10. Also, the horn won't work when the dome lights do work and visa versa... its crazy. I'm concerned about the headlight issue and will have him try this tonight. Glad I found this forum. From what I gleaned... could be cables or a relay. He doesn't hear the clicking that the other guys posted.
  • vkk2vkk2 Posts: 2
    I have a 2001 S10 with 4,3L engine.
    The right rear turn signal and the rear right brake light dos not work. The bubl is ok. I've switched the right and left bubl. I've also measured the voltage on both right and left sockets for the bulb, it gives the same reading.
    Any suggestion?
  • gonogogonogo Posts: 879
    Have voltage, ground problem.
  • vkk2vkk2 Posts: 2
    I've found the problem :O)
    It was a loose connection were somone had cut the wire to splice in another wire for I gues a boat plug or something!!!
  • chris326chris326 Posts: 1
    had the same problem exactly was actually driving and it died...replaced everything the same as you and it still wouldn't start 400 bucks and 6 mechanics later I pulled the distributor and it looked ok but replaced it anyways...when i compared the new one to the old one i noticed the old one had alot more "play" in it....think i paid under 100 bucks for it, ran like a champ pulling my 5th wheel ever since
  • zrokewl299zrokewl299 Posts: 4
    I have a 1998 Sonoma SLE w/ the 4.3L 4x4.

    I have the following electrical issues:

    Not working:
    -Rear passenger light cluster
    -wiper jets
    -Cruise control
    -Radio does not turn off w/ ignition (does turn off if passenger door opens and closes but not driver side)
    -Airbag warning on and off

    These were all issues when I purchased the truck, I just didn't realize it. Is it possible there is a single issue causing all of these probs or is it more likely there are separate issues for each one?
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