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Chevy Silverado and GMC Sierra Electrical and Computer Questions

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  • gbrewergbrewer Member Posts: 7
    I pulled the square fuses in the box under the hood, Not sure if thats what fixed it but its still working like new
  • champ72champ72 Member Posts: 3
  • champ72champ72 Member Posts: 3
    on my 7 way connector the two prongs horazontaly across from each other are my turn & brake lites. the turn lights work but i don't have brake lights. only on the plug the truck lights work fine. it has amber turn lights & red brake lights so there must be a converter some where but i don't know where. any thoughs
  • champ72champ72 Member Posts: 3
    well i found the problem on my own. it turns out the fuse in the panel in the side of the dash thats marked [cmhsl][ chassis mounted high stop light] controls the light on the back of the cab & also stops the trailer brake lights from working.
  • cbaker3cbaker3 Member Posts: 2
  • mustymusty Member Posts: 1
    I have a 1996 Chevy Suburban and the it has the compass and temp on an LED on the mirror. The compass works, but when I press for the temp it goes blank. Can anyone help me out. I do not know where the temp sensor is located to try to isolate the problem. Any help would be great. Thanks
  • jcuevas35jcuevas35 Member Posts: 2
    i have a 2001 silverado w/ the 5.3L vortech. check engine light started flashing and set code P0300. i swapped plugs, wires, coilpacks, injectors all with different cylinders and scanner still says its 7 and 8 misfiring. i even did a comresion test on both and got 150 out of both. scanner says it could be a possible sensor but names 7 different ones. anyone out there experience this problem or have any suggestions, thanks!
  • captain83captain83 Member Posts: 2
    Don't know if this will help you,but I have a similar problem with a 97 Silverado, 5.7 showing cope PO308 (misfire on # 8 cylinder)> I'm geting spark, and I changed the map sensor (problem still there) I just came from another site, where a techniciansuggested I take off the fuel rail & remove all 8 injectors. On the # 7 look for a rust build up. Then clean fuel rail & the top of injectors off with a can of brake clean. Then blow air through the fuel rail. Replace assembly and misfire will be gone. GM bulletin about fuel line rust on these vehicles. I'm going to try this next. good luck with yours
  • jcuevas35jcuevas35 Member Posts: 2
    i did remove #8 and #6, and swapped them to see if miss would move from 8 to 6 but had no change on scanner. i will try removing all of them as you suggest, checking for rust and cleaning them with brake clean especially #7. thank you very much! fyi: on another site, a similar problem was caused by a cam sensor and a crank sensor. ill try this first.
  • misterg57misterg57 Member Posts: 2
    HEEEELP! I HAVE NO BRAKE LIGHTS NOR TURN SIGNAL AT REAR, ALL FUSES GOOD, CHECKED ALL WIRING!!
  • gw1998gw1998 Member Posts: 6
    Cannot figure out why the back brake lights aren't working on my 1998 Cadillac Catera. ALL fuses are good. ALL bulbs are working. ALL lights work except the brake lights. I put my foot on the brakes..nothing happens. I recently had a new radiator installed. Did they hit a switch or an electrical wire under the hood? The brake lights were working before I had the radiator installed? I hope it's something simple. As soon as I get them working...I'm selling ASAP.
  • fathergoosefathergoose Member Posts: 2
  • diehardgatordiehardgator Member Posts: 1
    just bought 1997 1500 ex cab airbag light on Does anyone know how to resrt it thx
  • KCRamKCRam Member Posts: 3,516
    Since this is a Chevy Silverado/GMC Sierra discussion, you'll get a faster response asking in Cadillac Catera: Maintenance & Repair

    kcram - Pickups Host
  • takctakc Member Posts: 1
    have same code and condition.have u come up with fix
  • deducerdeducer Member Posts: 2
  • deducerdeducer Member Posts: 2
    '97 GMC Sierra 2500 all brake and tail lights intermittently burn out (black bulb). Is this due to a voltage/current spike?
  • malbitzmalbitz Member Posts: 4
    I just bought a cap for my 07 Silverado NBS. On the other trucks I have owned there was a wire ran to the back of the truck for the third brake light on the truck cap. On this truck, the cap dealer said there wasn't a wire. If you use the wire in the tail light, the 3rd/eye level light will blink with the driectional signal. The two local chevy dealers have not been able to get an answer for me. Has anybody ran into this? Or do I need to run a mire from the front of the truck.

    Thnaks in advance for your help.
  • geo9geo9 Member Posts: 735
    I don't see why you can't run a wire/splice off one of the
    taillights..............

    Anyhoo........What about running a tap wire off the trailer
    plug or the bundled wires behind the rear bumper?
  • malbitzmalbitz Member Posts: 4
    Taillights will cause the brake light to blink with the directional. There is not a brake only light (that I can find). If you have the brakes on and turn the directional signal on, both bulbs blink. In the trailer connection, the only output not affected by the directional is the Electric Brakes. But I don't know if there is a reason the dealer didn't use that one. Does anyone know if it is variable on the power output for the trailer brakes.

    I will look for the bundle of wires to see if I can find that.

    Thanks for the info.
  • jaselvisjaselvis Member Posts: 1
    I have two problems, first is the power window on the passenger side quit working last summer and then this winter the drivers side quit. When I push the button to operate the window there is no blink from the dash lights to indicate a power draw. Fuses check good and wires look ok. Second problem, the truck has a five speed fan and the first two speeds are not working. Blows fine on 3, 4, 5. I read somewhere that it could be the blower motor harness ? Thanks for any help.
  • obyoneobyone Member Posts: 7,841
    There are diodes that need to be replaced for the first two speeds on your controller. You will need to remove the front face panel of the a/c control to get to the diodes. Or you could do what I did and bought a replacement on ebay for $30. diodes are cheaper tho...

    If you have a meter you can check for power to the power window motor. Odds are that the motor is dead. Famous problem for the GM trucks. So much so that they stopped shipping the motor and controller together due to the high failure rate of the motor it was starting to cost too much money so now they sell just the motor without the controller.
  • obyoneobyone Member Posts: 7,841
    If you really want that bulletin you could get it for $14.95 at www.alldatadiy.com

    Just subscribe to your truck's year and it will list all 120 TSBs out on your truck. Who knows you might find other items of interest.... ;)
  • stoneysmithstoneysmith Member Posts: 1
    I issues started with a gage cluster going bad which I replaced about a year ago About six mouths age my heater fan started to cut out every once in a while seeming to draw on the system and to the point of reducing the idle and almost stalling out the eng. At the same time just once I tried to start the truck and when I turned the key I just got some clicking and the gages went a little crazy. After replacing the blower things seemed fine. Just last week the same starting issue has started up and even a low rough idle. I am not sure what to do but I know the dealer will just tell me to bring it in when it is having the problem. One other thing that is going wrong is my trailer tow will not activate I am a little werrie that I am driving a time bomb
  • bmli111bmli111 Member Posts: 2
    I have a 1991 GMC Sierra. Everytime I brake one of my 4 lights light up. MY taillights work. My right turn signal doesn't work either. I changed the bulbs. What can this be?? PLEASE HELP!!
  • bmli111bmli111 Member Posts: 2
  • dirtydog1937dirtydog1937 Member Posts: 12
    My guess would be a bad turn signal switch. You will need to pull the steering wheel and check it out. It's not that hard. Good luck.
  • dolphan456dolphan456 Member Posts: 3
    When you checked the wiring, did you check the junction board which is under the bed. The wiring bundle comes back from the front into a junction board and then is distributed to the lighting clusters. These connections are subject to water intrusion which corrodes the contacts.
  • misterg57misterg57 Member Posts: 2
  • 488488 Member Posts: 9
  • 488488 Member Posts: 9
    Looking for the brass plates/bushings that connect the wiper motor and the arm that transfers
    motor movement from the motor to the base of the wiper arm. 1990 and 1994 have the same set up. The plates unbolt form the transfer arm BUT
    gm will only sell the complete arm. A $5 part ends up costing $50 plus. So far no luck with the local jobbers.
  • cougartwincougartwin Member Posts: 1
    Yesterday morning my 2006 Silverado 3500 Duramax 9,900 miles,,,, would not start. GM had it hauled to the local dealership. Diagnosis was "LOT ROT" of the batteries. The service manager explained to me that the salespeople are "supposed" to start every vehicle every few days. If they fail, then the batteries drain. Their remedy is to get the battery cart and cables then jump start the vehicle. After this occurs several times, the batteries fail,,,,,,,, thus,,,,, LOT ROT. The dealership replaced the batteries. No charge. My concern is,,,,,,,, after all that "monkeying" around with charging,,,,,,,,,, have other components been weakened??? There are a lot of computer modules etc. This may be the beginning of several incidents. I am considering purchasing an extended warranty. I love this truck. I've had new Dodges, Fords, all diesels,,,,,,this one is the best. Thanks for your time. Cougartwin
  • 1offroader1offroader Member Posts: 208
    I'm no expert on diesels, but the electrical systems shouldn't be that much different than a gas pickup. In fact, they should be more heavy duty.

    That said, normal battery charging should not damage an electrical system. All you are doing is running a current to battery terminals, and cables, that normally produce such as current.

    Batteries die because they don't like to be run all the way down. I'm sure there's a physio-chemical reason for that but I don't know what it is.

    I would have the alternator/charging system checked just because a weak system could have caused the batteries to get run down. Otherwise don't worry about it - that's my advice.

    1offroader
  • flysprayflyspray Member Posts: 15
    Where did you find a cap for the NBS 07 silverado... Ive looked and couldnt find any. My truck should be in real soon. I ordered a cap from the dealer... and they are not available yet. I also have a question about the lockable tailgate. Does the factory lockable tailgate work with the keyflop???
  • malbitzmalbitz Member Posts: 4
  • malbitzmalbitz Member Posts: 4
    Century Truck Caps is where I got the CAP (Ultra). Leer also makes one for the 2007 NBS (100 R) or something like that. Also Glasstite had one at the time I bought mine.

    I do not know about the lockable tailgate. Sorry.
  • marcb2marcb2 Member Posts: 9
    I have a problem with my right turn signal that has gotten worse since I bought my 2003 Silverado 1500. Now, a majority of the time when I turn on my right turn signal, both the left and right blinkers come on as if I had turned on my hazards. Any suggestions on how to fix this or where the problem might be? Please feel free to e-mail me at marcbuchanan@yahoo.com with Turn Signal as the subject.
  • renegade87renegade87 Member Posts: 2
    Last week my truck started having electrical problems. When starting the truck after the engine started, you would hear a whirling sound in the dash, similar to the ventilation "switch" inside the dash, then a quiet thud, and the clock would reset on the radio (standard issue radio - AM/FM/CD). That happened 3 or 4 times and stopped. This morning I was driving and all my gauges went dead as if the truck was shut off. The heads-up display still showed "instant mileage" (love to watch that) and all gauges were dead. I stopped, shut it off, browsed the manual stupidly thinking in might be a fuse. I restarted the truck and it's fine. What's up with this? I love my truck, but it seems possessed with an electrical gremlin.
  • renegade87renegade87 Member Posts: 2
  • jolazanjolazan Member Posts: 1
    Have you been able to resolve the problem yet? I have a 2004 Silverado (just out of warranty of course) on which the same thing just started happening... Any input is appreciated.
    Thanks
  • marcb2marcb2 Member Posts: 9
    I have not received any feedback. I have talked to a dealership who wants $80 to run a diagnostics on the truck, plus fix the problem. If it turns out to be something simple and inexpensive id rather fix it myself but need to know what the issue is first.
  • arkz71arkz71 Member Posts: 10
    I have a 2003 Silverado Z71 5.3 and I have extended warranty I have about 99,500 miles or so. They replaced mine because the parking lights were coming on after the truck was shut off. I think the part was about $260 or so, I did not pay anything for it, but the $900 warranty from Millienum has more than paid for itself.

    If the passengers door loses all power it is the module in the door, other than that it has been an excellent truck. All vehicles have the same computer module problems the more the EPA and all of the Gov wanting complete control they will only add more electrical items.
  • mhorvmhorv Member Posts: 1
    I had the same thing happen to my 2004 Sierra. Within a couple of months of this happening, one of my headlamps went out. I replaced the headlamp and haven't had a problem since. I'm not sure if it's coincedence, buy would be interested to hear if it remedies your problem.
  • josea1josea1 Member Posts: 1
    I have troubleshooted this and am stumped. I turn the key and the engine doesn't turn over and all you can hear is the noise the relay makes. I ran a test on the truck and no codes are pulled. I'd appreciate any advice or suggestions on how to find what I need to fix. Also, does anyone know if this truck has a kill sensor?
  • marty97marty97 Member Posts: 2
    Just bought a 97 Sierra 2500, 92M miles, checked out by a mechanic. Runs fine, but everytime I drive to my cabin, at about 100 miles into trip (same spot in road on MN 48 25 miles E of Hinckley, MN) ABS light comes on, speedometer drops to zero, then flutters, tranny slips/cluncks, and can only go about 30 mph. After a while everything returns to normal. We've run it farther distances on hot days, even pulling boat - no issues. Mechanic is mystified - no codes. I love this truck. Please help!
  • cabinetguycabinetguy Member Posts: 1
    we had the same problem with a 2003 Envoy, it turned out to be a problem with the ignition and was resolved once the dealership replaced it
  • chad8chad8 Member Posts: 9
    I have 01 sierra that has a very strange problem...the batteries(3 so far) I put in this thing leak(or boil) acid and don't last long...I have checked the grounds thoroughly and the cables are in good cond. I have rebuilt the alt. and also replaced it all together just to rule it out. It shows a good charge(not over) on the gauge and also with a meter. If anyone has any ideas they would be greatly appreciated
  • sparkie3sparkie3 Member Posts: 2
    Hi, I have a 1998 Silverado and the battery goes flat after a couple of days of just sitting around. I found that I had 2 Amps going somewhere on the lighting circuit ( 50A fuse ) when everything is turned off. I checked everywhere and I cant find any lights that are still on. This fuse also powers the remote locking of the doors.

    Any help would be much appreciated. does anyone have any lighting circuit diagrams or any advice on where I should start looking.

    Thanks.
  • ripthelipripthelip Member Posts: 3
    Hi-

    Do you have an alarm on the truck, or just the stock security system? If you have an alarm check the brain of the alarm to make sure all of the connections are tight and there isn't an open circuit.

    Ripthelip
  • english_andyenglish_andy Member Posts: 2
    Try checking the tensioner wheel as the bearings wear out and cause the belt to slip. The wheel is (looking at the engine from the fender end) just to the left of the altenator. If it knocking or if it wobbles replace it ... a replacement costs about $8 ... the altenator maybe at fault on older vehicles ... I drive a 1989 Silverado and another problem ... especially for me as I live in the UK ... is that damp can affect things too so use lots of grease on connections or something like WD40.

    It could be the alarm ... or it could also be an earthing problem too ... again ... check all the earth connections and tighten and grease too.

    I had a kill-switch fitted to stop battery drain all together.

    Another issue of retro fitting of radios and stackers and under chasis lights etc. Again, check all of these.
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