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Chevy S10 - GMC S15 and Sonoma Electrical Problems



  • gonogogonogo Posts: 879
    Well seeing it's the driver side, I would suspect the wiring when it enters the door.The opening and closing the door has probably broken the wires.
  • wborenwboren Posts: 1
    i have the same problem, any positive feed back on this? any help would be great
  • I have a 2002 Chevy S-10 Crew Cab Pickup. The fog lights and ashtray lights are not working, I checked the bulbs and fuses and they seem to be fine, is there a relay that could be cusing this problem? Also the window control switches are not working in the passinger and rear doors, but the the windows roll up and down fine by using the drivers side controls. How do I fix this? :confuse: and is it linked to the fog lights and ashtray light not working?
  • Hey. I have the exact same problem as you on my s15. Everything was working fine, until I decided to replace my license plate light sockets and bulbs. Now my parking/ running light stopped working but my signal and break lights still work???

    Did you find a solution????
  • I have an annoying light problem, having trouble fixing!
    My license plate lights weren't working so i decided to change the sockets and bulbs, apparently big mistake. Now my drive lights in the front and rear are not working along with my dash lights and passenger side courtesy light. But my break/signal/reverse/head lights are all working perfectly. Im thinking this may be a ground issue..... need help!
  • I am having to guess here but if you have a trailer wire harness attached, it may have rubbed and grounded itself out. Ground issues on the S series seem to be an issue and with a bazillion grounds it is tough to trace which is the culprit. Also I have heard that putting bulbs in that are not the exact appropriate bulbs will jack up the system as well.
    I love my S10 but the problems are frustrating. Its a truck. It should be simple. Good luck and let us know what you find.
  • the_big_althe_big_al Posts: 1,079
    I also point to a ground issue... I just fixed one on my truck involving the turn signals in the rear. Might try and see if you can locate an electrical schematic to see what is tied into what (that may or may not help since a lot of things are tied into one thing or another depending on what is being used or not used), or just start tracing wires. I would start at the license plate lights since that is where the problem started and go from there. Trace all the wires connected to them and see if there is a wire rubbed bare or corroded.
  • esw03esw03 Posts: 2
    I have a 1997 S10 ZR2. Last night I changed one of the headlights while the truck was running, so the daytime running lights were on. After changing the headlight, the power windows, cruise, heater mixing whatever (?) won't work, and the ABS light is on all of the time. I have checked all of the fuses and breakers and they are all ok. Does anyone have any ideas on what could be wrong. Thank you in advance.
  • gonogogonogo Posts: 879
    Try removing the negative battery terminal for 10 minutes, maybe a processor will reset.
  • esw03esw03 Posts: 2
    Thanks "gonogo" !! Believe it or not, a couple of hours after I posted the question, the problem just went away. It worked great until last night. I started my truck and all of the previous problems had returned. I unhooked the negative battery terminal for about 30 minutes but it didn't fix the problem. Does anyone have another idea.
    Thanks again!!
  • gonogogonogo Posts: 879
    Intermittent uh. Check for power at the fuses where you have lost power. Cruise , HVAC etc. The ignition switch maybe the problem, not the key one, the electrical one.
    If you can tell me which fuses don't have power, I maybe able to trace it to the ignition switch.
    A 12 volt test light is real cheap.
  • elmo7elmo7 Posts: 1
    I have a 96 S10 V6, I need to find the oil pressure sensing relay
  • q48q48 Posts: 1
    I have a 2002 S-10 4.3 4WD. The problem I have is the tachometer flutuates(pings) whenever I hit passing gear or go above 2300 RPM. It also flutuates when going downhill or letting foot of accelerator and then reapplying until engine catches up to tach speed. I had alternator, crankshaft position sensor, Camshaft position sensor and distributor replaced. Tune up is all new (plug, wires cap and rotor). New transmission was done 3000 miles ago but problem existed before. I really need an answer to this because I drive 100 miles every night to work
  • I have a 1988 GMC S15 and the tail lights/ dash lights dont work with the engine on or off. I checked all the bulbs replaced them and put them in and turned the headlights on and the fuse kept blowing. ive checked every other fuse and they are fine. I realize that it is a short in a wire somewhere but I have looked everywhere from the taillight sockets to the cab behind the fuse box and havent found any shorts. what should I do?
  • I have a 97 S10 with the 4.3 X-vin MT, when i let up the e-brake, turn the headlights on, perss the brake pedal or sometimes when i put the truk in reverse i get what seems to be a circut overload. Some times the radio will turn off and then back on, sometimes the truck will bog down like tis got too much fuel, and sometimes the enire truck will turn off if i let the idle get to low when it bogs. And very raily (but is has happened), the truck will turn off and on all on it's own while driving down the road without touching anthing at all. Ive been messing with it for months, battery good, alt. good, changed the light switch and check all the connections under the dash and all the body grounds and they are all good...any suggestions?
  • monsonmonson Posts: 5
    i have a 1995 sonoma s15 which has been a very good truck, 3 months ago i would turn on the turn signal and both lights would flash. i did some checking and someone said to check the bulbs. the cleaarence light was burnt out so i replaced it and the problem was solved. now i have the same problem when you turn on the tailights there is none, when you hit the breaks the light comes on and stays on but is dim. you then have to turn off the headlights. also the clearence lights are very dim. we also noticed the tailights would flash and then the top brake light would flash. it looks like a squad car going down the road. lite bulbs are basically dim. any feeedback or ideas i just got the vibrations fixed on the car. whether it has nanything to do with it t he car radio has power but no sound comng out of the speakers
  • Dim lights are usually caused by bad grounding. Take a jumper cable and connect one end to a known good ground. Connect the other end to various places on the chassi near the lights and see if that makes them brighter. Also look for loose connections or a loose fuse for that circut. If your brake light is sticking on, it is usually a faulty brake light switch. First fix the dim light problem though.
  • the_big_althe_big_al Posts: 1,079
    I second the bad ground. I had an issue a few months ago with a bad ground. It dealt with the turn signals. When I would use the signals, it would basically make all the lights in the rear flash in someway. The reverse lights wold flash like a turn signal, the license plate lights would also be part of the pattern. In short the rear lights had issues when I used the turn signal.

    I traced it to a bad ground under the rear frame right before it branched out to the trailer wiring. Check the wires coming from the lights and then under the truck. Especially check areas that are exposed and prone to road and water grime, or even under the hood where heat and oil can possibly affect them.
  • Thanks for the info guys i"ll try the grounds to see if i can find something. i did notice the front turn signals are bright so there is no problem with them. I just figured they wee on the same circuit as the tailights but evidently not. i wasnt sure what grounds to be looking for but now i have an idea where to start.
  • jima3jima3 Posts: 1
    I have 2003 S-10 4wd with an automatic transmission. When you get the tuck moving the it appears to be okay, but when you put you foot in the gas to pull out, the RPMs go up to 3K but it doesn't shift gears. The fastest this truck will move is 40 MPH. The other interesting thing is the MAS keeps trowing a P0101 code. I replaced the MAS and traced the wiring back to the PCM.

    Could this be a bad PCM?

    :cry: :sick:
  • Where would i find the ECU on a 97 s10 pickup LS?
  • gonogogonogo Posts: 879
    Not sure on a 97, it is either under the hood on the passenger side or behind the glove box.
  • I have recently bought a 99 Sonoma SLS, my problem has to do with the brake lights. It's seems if I turn off my truck under low light conditions, my brake lights, on the box (not the one above the window), remain on. I checked the bulbs, they are the correct ones. I am thinking it may have something to do with the automatic light sensor. Anyone else run into this problem?
  • madmattermadmatter Posts: 2
    edited February 2010
    Hi, this is my first post!
    I drive a 2000 Chevy S10 with a V6 motor. The truck has issues. Over the past 3 years there have been 5 one week periods where the truck does not want to be started. Here is a rundown of what happens.

    First I open the truck door. Then I sit down and close the door. I turn the key sometimes I turn it fast and sometimes I turn it slow. While turning the key slowly the truck goes through its normal starting phases. It shuts off all the unnecessary electrical systems, then right before the engine turns over it gives off one, two maybe thirty clicks (think video game machine gun sound) then the truck dies.

    When I say the truck dies everything goes out it loses all power. The horn doesn't sound, the power locks don't work etc. Once dead the truck demon does one of two things. It may flicker all the speed/rpm/gas gauges then a few seconds later it magically turns on or the truck stays dead. The truck stays dead for up too two hours before magically regaining power.

    The weird part. If the truck stays dead and I connect it too another vehicle via jumper cables. This seems to give it a better chance of a successful start (although the battery is fine) And even when connected via jumper cables it may still die, but if I wiggle one of the jumper cables, the truck instantly snaps back to life for me to chance another start. It takes an average of 20 start attempts before the truck will start and that's with or without the jumper cables.

    So an overview of the Electrical Demon, I turn the key, the truck dies (electrically dead), I either A wait or B fiddle around with the battery connections to try and arouse the truck back to life. Once the truck regains electrical consciousness I turn the key again cross my fingers and hope it starts. If I don't turn the key to the start position, the truck is usually fine (although not always). If I use jumper cables the truck seems to respond better by starting sooner. It takes up to 30 tries for a successful start. Once it has been started successfully It runs fine until I shut it off.

    Need Good Advice Soon Sincerely,
  • the_big_althe_big_al Posts: 1,079
    If you say the battery is good, then I would look at the battery cables. It sounds like what you are describing is actually a bad battery, or the symptoms of a bad battery. So if your battery is indeed good, then look at the connections. I suspect this is your problem because you say the truck runs fine after getting it started so the issue isn't with the alternator or the connections after. It is between the battery and the starter. Even if the cable looks good, there still might be corrosion inside the cable that is not visible. Check there first and see if that solves your problem.
  • When I say the battery is fine, I mean to say the battery is charged. It holds a charge fine, but I am unsure if the battery has some undetectable issue (internal short-circuits) or if the cables are corroded on the inside. Everything appears to be fine on the outside. I did have an amplifier and a new CD player installed two years prior. The amp is 200 Watts which is very small in my opinion. I do not know if this installation is somehow related to this problem since this problem existed before the amp was installed.

    Some other magical happenings with the truck:
    1. The lights inside and outside the truck flicker with the music on the radio.
    2. The lights inside and outside the truck flicker even with the radio off.
    3. When the gas gauge is below 1/4 of a tank the abs light comes on. There is no problem with the anti-lock brake system. The sensor is incorrectly working and seems to be correlated with the gas gauge in some way.
    4. The horn works half of the time, when they test it in the shop it works and when I need it on the road it doesn't. The shop said the horn was fine. I know from experience that is only fine when it wants to be and when I want it to sound it refuses.

    If you were to witness all these events and know the truck as I have come to know it you would be certain it was haunted. This truly is not the case but the issue seems more complex than the cables being bad (although it would make sense if they were. The battery could be bad but this is the second battery in a row that has been faulty. I'm wondering if the truck could make batteries bad or if batteries are bad before they are put in the truck.
  • the_big_althe_big_al Posts: 1,079
    edited March 2010
    Hmmm... I still lean towards cables. At least as a place to start. A bad cable connection can cause a battery to go bad. You might also have a bad ground somewhere. That would cause lights to flicker when a load is placed on them - i.e when your radio is on. A bad ground would also cause lights to flicker with no load placed on them. Check you major grounds. A bad ground wire from the battery to the starter is one place to start. Also check the ground from the alternator. I'm not an electrical genius and I am pretty much shooting in the dark, but if there are several systems going wonky, then I would check at the main sources of power - the battery and the alternator. You could have a bad alternator too. That won't help with the starting issue because that is a battery only system, but a bad alternator could be causing the flickering too in that it won't be able to keep voltage up when a load is placed on it. It could also cause a battery to go bad in that it doesn't send enough juice or amperage back to the battery to charge it fully... It's a vicious cycle. Check cables. Replace them if needed. Have the alternator checked out. It's not uncommon for them to go bad.

    I have an amp on my system and have had for about 5 years and have never had a flickering problem. I had a 500W amp and now a 250W amp and the lights don't flicker at all when the truck is running and only slightly when the the truck is off. Make sure the amp is properly grounded to the frame or floor of the cab. I am on battery #3?? Maybe #2 since I have owned the truck (7 years) and alternator #2. The only time I had an issue was right after I put in alternator #2 and the cables weren't tightened properly. I had starting issues exactly like you described. I cleaned all the connections to the battery and the tightened them all up and haven't had an issue since.
  • agrivateragrivater Posts: 2
    edited March 2010
    :confuse: I have a 99 chev S-10, it fires up and runs for about 2 seconds then dies.. As long as I squirt starting fluid into it it will continiue to run, and before yu go to the obvious. It has great fuel presure!! Something is telling it to shut the fuel off..

    My "security light" flashes 3 long single, followed by 2 quick tight flashes.. Does anyone kno what this code is trying to tell me?? Or does anyone kno where I can find a list of the code definitions?? :sick:
  • I have a 99 chev S-10, it fires up and runs for about 2 seconds then dies.. As long as I squirt starting fluid into it it will continiue to run, and before yu go to the obvious. It has great fuel presure!! Something is telling it to shut the fuel off..

    My "security light" flashes 3 long single, followed by 2 quick tight flashes.. Does anyone kno what this code is trying to tell me?? Or does anyone kno where I can find a list of the code definitions??
  • gonogogonogo Posts: 879
    This thread tells you all the fixes for the security won't start issue, you like to read.
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