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GMC Jimmy Electrical System



  • keanijoekeanijoe Posts: 5
    98 Jimmy...takes 4 attemps to start in morning...great in afternoon. Runs bad at light throttle,,,,if I floor runs thing that is the morning...I start the truck and only the left side speakers work...truck runs bad....afternoons...both side speakers work and the truck runs great...I'm not crazy and know speakers don't make the truck run bad but the two have to be connected...It has to be some switch ...I think...also sometimes when only left speakers won't work...could it be the ignitiion switch?
    Or...could I just be CRAZY......... and crank sensor...distr..pugs..wires...
    I get codes telling me it misfires....and sometimes is -7 off in timing...but I can't turn the's locked down...HELPPPPPP
  • trikdaddytrikdaddy Posts: 1
    I have a 2000 GMC Jimmy SLS 4x4, 4.3L, 2Dr. I keep hearing the flasher (behind the glove box) clicking. Has done this for the last year I have owned it. I have replaced it (27.00 from dealer) and still clicks (they would not even take the part back even though I was in the lane outside customer service). When I press the brake pedal, the clicking stops. Take my foot off, the clicking continues. I disconnected the brake switch, and the clicking continues. All lights, flashers and blinkers work properly. Blinkers/4 ways do not flash unless turn signal/hazard switch activated. Still the clicking persists. Any help on resolving this issue would be very appreciated. Thank you very much in advance.
  • Hi guys...I have a good one here that I'm hoping one of you can figure out for me.

    I have a 1996 Jimmy that I put an electric over hydraulic plow on. I put a second battery in it to help with the draw. I used it all last winter and when everything was running (lights, defroster, rear defroster, rear wiper, front wipers...when I actuated the would draw down to @9 volts at an idle to 1000 rpm. I decided to put on a larger output alternator for this coming winter and bought a 155 amp unit and also the recommended beefier wiring kit with a 175 amp fuse in it. I installed everything and ran the vehicle with everything going and actuated the plow several times. It still drew down to @ 10 volts but recovered much quicker. I shut it off and since it's just used for plowing, I didn't start it again for a week or so.

    Recently, I started her up and immediately noticed that the voltmeter was registering about 9.5 volts with no load on anything. I called Napa and had them ship another one. I took my new one in and the guy bench tested it and said it was good. He also tested the new one they got for a replacement and found it to be bad so he ordered a third one. I installed this one and it worked fine. I started it up the next 3 days in a row and it was charging just fine...but the 4th day, it did the same thing. When I started it up, it wasn't charging. Something happened to both alternators between the time I shut off the vehicle and the alternator was the next time I started it and it wasn't.

    I believe I should have 12 volts at the charge cable end at the alternator at all times...I do. Also, the "L" terminal coming out of the harness at the alternator should have 12 volts when the ignition is in the RUN or START position...I can't confirm that. I don't have a test meter...just a 12 volt trouble light and I'm not sure I'm making a good connection to that small pin but I had these conditions before I installed the second alternator and it worked for 4 days.

    I don't understand what has happened...why the new alternator will work for a while and then just stop working while the engine isn't even running. I just replaced the original 105 amp alternator with a higher output one...and I installed the wire upgrade kit that goes with it.

    What does that "L" pin go to? Does it have something to do with "exciting" the regulator? I think I read that it could have a resistor in the line somewhere. What does it look like, where is it located, and how do I test it? Can you enlighten and help me...PLEASE? :confuse:
  • I have a 1997 GMC Jimmy 2WD 4.3L engine that I need a wiring diagram for. I bought a Haynes repair manual , but it doesn't seem to come close to covering my vehicles wiring. My jimmy had a fire under it at some point in its past and melted a large switch assy on the side of my tranny. It seems to select lights (reverse etc) among other things, but its all kind of a mess now. Where can a guy obtain this info. Thanks.
  • I think something is draining the battery. I replaced the battery and the alternator but that didn't help. I checked the fuses and they all look ok. I was thinking maybe it's the positive cable on the battery, but I'm not sure. I'm not familiar with the electrical system. I just tried to start the truck and there was power. As soon as I turned the key everything went dead. I'm going to get this battery charged again and take it from there. If anyone has any ideas, I'ld love to here it. Thanks in advance.
  • you have a bad connection somewhere, you can check the positive post to make sure it is not broken, that happened to me once, or your possitive cable is corroded somewhere down the line.
  • My brother was driving his Jimmy the other night when without warning he lost all electrical. He didn't even have a slighty flicker of power once it died. I asked him if he smelt anything hot like there was a short somewhere and he said NO. I checked his battery and it had more then enough power to turn on dome lights yet they wouldn't work. Everything is dead. We don't know what the problem can be, we looked at the ignition switch and I don't see anything wrong with it but not quite sure how to test it. What would cause this vehical to just loose electrical power without any warning?
  • My son's 97 Jimmy has the same problem as electric power anywhere. The other night we had to tow it home after it died from what we thought was a bad alternator. Headlights going dimm, stalled out, wont start, and when the jumper cables were removed it died. So the next day we spend some rent money on a new alternator and battery. Now theres nothing. No power anywhere. I've checked all the fuses I could find, and we took the covers off around the ignition switch and no power to any of the big wires going to the switch. We cant afford a mechanic and if he dosen't have it monday we're screwed....any ideas???
  • Well after my original post I took the battery to be checked. Although it was a new battery, it still needed a charge. I figured something was killing the battery. Since I charged the battery I haven't had a problem. I did figure out that if the break release was not pulled hard enough, the dome light would stay on. That might have been what was was killing the battery in the first place. I don't think that's your problem though.
  • well after a $190 repair bill we were informed that we had left a wire unhooked from the alternator...when we put the new one on it got trapped under it and we couldent see
    but thanks for the help guys.
  • only the top beak light works not the 2 lower or er lights how do i fix
  • OMG, Someone who might know what the trucks plight is............Our you saying if ya press this button ( to right ) of light dial...Daytime driving lights go out..........So then if one pushes this button 4 times while driving ( please define while driving...or truck just on and idal) 2 weeks working and searchin on net....with no answers yet..........
  • Ok.......Read your post 10 times now and see my questions is confusing..........I fear I might have pushed this button 4 times while driving ....and my headlights are out...........Questions is then how do I reverse what I have done..........Get lights to work again.....
    TXz Knowledge would be greatly appriciated first truck and had it a month....and have to park it :cry:
  • my 1998 jimmy had a code number 6 misfire. come to find out it was bad distributor. Replaced distributer now works fine
  • best way to fix abs light is to replace whole hub. take to shop that reads abs codes to find out which hub right or left.
  • mine done the same thing. the button on the emergency flasher was dirty. there is a spring under the button some times gets stuck. It sounds weird but thats what it was
  • did u ever find out the problem,with the clickin goin on ,if so pls let me know ,,tyvm
  • tyvm ,,much app:))))
  • 97greenjimmy97greenjimmy Posts: 4
    edited December 2011
    I have 1997 Jimmy 2WD with a 4.3 and 124,000 miles, I'm the second owner (had it 10 years). I searched these forums and found out that most likely my ignition switch was the cause of my int. lights and dash lights going on and off as well as the failure of the power seats, locks, and windows in addition to the AC/heat/blower not working. I (with a lot of help from my stepdad) changed this out today. I reconnected the battery and the vehicle has power, and at the very least the windows and blower are working normally. But it will not start. We had to dissamble a lot of things including removing the lock tumbler (cylinder?) and I'm wondering if it didn't go back together right or I need to reset something? When you turn the key foward, there is just a click and the running lights dim. My Stepdad says I need a new battery because mine is 2 years old and probably bad. I have had no trouble whatsoever starting my truck previous to today and I think it just drained down. However, we couldn't get it to start even hooked up to his truck with jumpers. Is it really a coincidence that my battery has gone bad the same day we took apart the ignition? Is there anything I can try? I don't want to spend money on a new battery and hook it up and it still won't start. Anyone have any advice for me? I'm putting on a charger for now but my stepdad says I'm going to have to buy a battery too. Thanks! :confuse:
  • i personally wouldn't buy any battery if it started the day before, charge and double triple check your wires, might be a ground off, i myself have a clicking, blicker problem that is in the steering colunm but not have done it yet it actually got better. check all wires make sure nothing shorting out did you disconnect the battery before any work was done. neg i believe, i forget myself sometimes. check fuses, the ones under the hood, sorry this is about what i know with electrical. let me know. thanks
  • It was kind of annoying, at the very least you can take a battery out and have it checked for free, but it's dark by 6 pm, everyone was in a rush and I needed my truck running. I suspected it was something else, but he got a new battery and installed it--no change. After I got home from work I went to my poor dead truck and checked it out. The cable going to the positive post was wiggly. I unhooked it, let it sit 10 minutes, and then tightened it down as snug as I could without feeling it would break lol. Then I did as I had read would reset the computer, by turning the ignition off and on 3x, then turned it to start. Cranked up first try with no hesitation. I may not have pinpointed the exact problem but WTH it worked. Not too bad for a middle-aged divorced mom! My stepdad said I made him look bad :P Everything works now except the power locks and that's another story. Thanks all for the advice this forum has been a life-saver for me.
  • Hey there everyone. Just changed out the ignition switch (the multifunction one with the wires) on my 97 Jimmy 2WD and now the power windows, fan blower, etc are all working again and the ABS/brake warning lights no longer flash on and off etc. etc. But I need help with my power locks--I had taken it to the dealer when the electrical starting going whacko and they charged $300 in labor but didn't know why it wouldn't work. My then husband (now ex) tried a lot of things to fix it and had no luck. The locks work manually, but the remote wouldn't funtion nor the power switch so I couldn't lock the back hatch either. I know he had taken some parts of them I have on my desk here it is a "remote function actuation module" and I don't know where it goes. I thought there was another part of a similar size but heavier but can't find it. I also don't know where the remote is since it quit working years ago. I called my ex but he said he can't remember what he took out or where it goes and won't help, his new wife doesn't like that. :surprise: So besides possible missing parts and not knowing where they go--would it even still work if it hasn't been used in years? It's not the worst thing not having power locks--not nearly as bad as no windows/AC in FL in the summer, but it just seems incomplete as it's the only thing not functioning after all this work. Are there manuals or anything I can get that have things like this? Any help appreciated! :blush:
  • hoping somebody here might have an idea on how to isolate the passenger door lock during unlock only, my alarm sends a neg. output for this but the system is reverse polarity wich means the wire rests at ground but of course when I try to lock the wire from the alarm to the relay I used is not providing a ground so it wont work, any ideas on making this work?
  • I just took my 1997 GMC Jimmy 2WD/4D in for an electrical check less than a week now for the following problem and the mechanic could find nothing wrong.

    1. I go to start vehicle by inserting key in ignition cylinder
    2. All Dash lights and gauges working
    3. As soon as I put the key in the start position, all power goes completely dead.
    4. Battery checked out good and electrical system checked out good when I took the Jimmy in to find the problem.
    5. Key will lock in on position until power resets about 3-5 minutes or longer, before I can turn it to the off position.
    6. key will turn to accessory position and radio, headlights, wipers will work.

    Of course the problem didn't occur while at the mechanics, but I did describe the issue I had prior to bringing it in, now it is doing the same exact thing again, strange thing is sometimes it will start, other times it will just kill all the power to everything, lights, DRL, radio, everything is dead, BUT, once the power is restored, as shown about in #6, most things start working again.

    This problem has me completely baffled as to what to look for or repair. I'm thinking the ignition switch may be the problem, but not really sure.

    If I knew which wires to "short" together in the wiring harness, I'd take the ignition switch out and see if the car would start by bypassing the switch. But I have no idea of which wires are what and I haven't yet taken the steering colum apart to get to it.

    Before I do, I'm trying to determine just what the issue is that is causing this particular problem. I've never had a car act like this before when attempting to start it, power go completely dead and then be restored a little later. So I'm at a loss as to what to look for or the cause.

    Any help would be greatly appreciated!
  • michael79michael79 Posts: 21
    edited February 2012
    check starter, sounds like a loose connection to me. their also might be a fuse for the start. not sure about that i have a 99 and never had this problem, (yet) 223,000 and still kicking.
  • Thanks Michael.

    A couple mechanics stated to look for a bad or loose ground wire as well. I did that, even replaced some ferrules and regrounded. I can't find any loose wires, nor can I figure out what is creating this issue. I've looked at the fuses under the hood as well as the ones inside the car and can't find any problems. So this one has me completely baffled.

    Looks like I'm just going to have to have it towed to my mechanic around the 15th of Feb. to see if they can figure out the problem. Just had the electrical system troubleshot on Friday Jan. 27 and they said everything was fine, this was the same reason I took it in, but then it started and didn't do this at the mechanics. So it's a bit frustrating not knowing what is creating the problem.
  • On my 2000 jimmy my fuel pump was bad and it caused the truck to turn off while going to a stop. Sometimes it would make it seem like the battery was dead and all the guages would turn off.The truck wouldnt turn on right away . When you brake to come to a complete stop does it turn off on you? If it does look at your oil meter and see if it goes down. I replaced the fuel pump and it was like new. I hope this helps you out. If it is your fuel pump and your gonna do it yourself and dont know how just message back and ill walk you through it.
  • lightman13lightman13 Posts: 5
    edited February 2012
    Nope, have never had any stalling issues with it at all. None of the gauges went down.

    It just goes dead when the key is placed in the start position to crank the car and get it going.

    Other than that everything else seems to work just fine on the vehicle, just can't start it because it goes dead.
  • did you ever find out how to remove security system i need to know how mine is really messed me if you can thank you...
  • i so need to know too please help us....
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