The Stupid Electronics Questions Thread

[83GMCK2500]

Where is the module or ecu located for remote keyless entry? My door locks are going haywire.

Stand on your head, look straight up from accelerator pedal. It is behind a metal bracket if memory serves, it's a PITA to get to.

 

[Erik the Awful]

Check the door lock switches in your doors as well. If they're getting water in the connectors, put some Nye lubricant in the connectors.

 

[BowhunterBrown]

Thanks guys. I think I fixed it. I replaced the relay, above accelerator pedal and no haywire business so far. I found the relay, popped the cover and watched it in action while cycling door locks. One side (I think it was the lock side, as opposed to unlock side of relay) gave a pretty good arc when engaging/disengaging. I could of tried cleaning the contacts but opted to just replace it. So far so good.

 

[Tubbz]

The taillight/brake bulbs have two lighting elements, each on a different circuit, but with a common ground. Check your bulbs to see if one of the elements has broken and laid over on the other. Having your taillights on will backfeed the brake light circuit and pressing the brakes won't make any difference because there's already current there.

At the same time, during the day when you press your brake pedal, all your parking lights will light up.

The taillight/brake bulbs have two lighting elements, each on a different circuit, but with a common ground. Check your bulbs to see if one of the elements has broken and laid over on the other. Having your taillights on will backfeed the brake light circuit and pressing the brakes won't make any difference because there's already current there.

At the same time, during the day when you press your brake pedal, all your parking lights will light up.

Just a quick update so I managed to get my taillights to work at night I just swapped out the headlamp switch but now my taillights won’t turn on unless the front headlights are off. When I turn on the front headlights I no longer have any lights to the back whatsoever. Also when I’m at a stop sign and I put the blinker it blinks normally until I release the brake and go forward then it starts blinking fast could this be a ground issue?

 

[97blackbowtie]

Just a quick update so I managed to get my taillights to work at night I just swapped out the headlamp switch but now my taillights won’t turn on unless the front headlights are off. When I turn on the front headlights I no longer have any lights to the back whatsoever. Also when I’m at a stop sign and I put the blinker it blinks normally until I release the brake and go forward then it starts blinking fast could this be a ground issue?

Very similar to my issue.
So I swapped new taillight circuit boards(Dorman brand, soon to be returned to AutoZone just in case) and all new bulbs. I'm worse off now than I was before lol
Before I didn't have reverse lights, no brake on driver side. Now it's no taillights, brake, or turns with the headlights on. Headlights off, I have brake lights but left turn lights up left turn and reverse light AND right side turn signal. Same vice versa and still no reverse lights with either the headlights on or off.

 

[steveed]

I would trace all the wires and to verify the circuit board matches the pinout of your harness.

This thread has links to the GM official electrical docs, they even have good troubleshooting steps.

88-98 Service Manuals

Over the years I have collected a bunch of GM service literature. Links to PDF Scans of service and STG manuals and a links to the Parts manuals. You'll need the FREE Adobe Acrobat reader to open these files. Get it directly from Adobe here {http://get.adobe.com/reader/} If you're not...

www.gmt400.com

I bought a new rear taillight harness from ebay and I ended up have to swap a couple of pins to make it work properly. Nice harness but I don't think things are as cut and dry as they think when the ad says it works for 88-99. Connectors might be the same but the wiring might be a bit different.

 

[97blackbowtie]

Steveed, I figured this was my next journey. Thank you for the link/info. I was just hoping someone could tell me where exactly to tap the fender wall with my magic hammer to make it work right again ‍
I am currently using magnetic trailer light set with the plug-in adapter that works fine. I tested the connection plugs at each taillight and the circuit board had little test spots on the back. That was when I realized the boards had some cracks in them. Local AutoZone guy is really helpful. Going to take it up there tonight and have him give me a hand if he's not too busy.

 

[professur]

Forgot to update/close my post. Turned out I did have a second broken ground ... the one from the body to the frame, and the one (same bolt) from the frame to the back of the engine. Wasn't physically broken, but was super crusty. That resolved the no crank issue. Which led to crank/no start ... caused by a noisy fuel pump that suddenly went quiet. Which fell out of the completely corroded fuel tank when it was dropped. And a broken rear brake line. Not sure why I just dumped a grand into a truck worth $500 when the price of gas is $1.50/l ... but I did.

And then the entire exhaust fell off my Aveo.

 

[Threequartercrewcab]

I just bought a 2000 K2500. Does anyone know if the LMC heavy duty headlight harness, and 4 hi kit will work with my truck? Or if anyone has any other recommendations as for what would be available?

 

[PlayingWithTBI]

@5vortec7 makes a nice kit.

HD Headlight Harnesses w/ 4 High Mod

Here’s my version of the HD headlight harness. Delivers a full 12v to headlights through 12 awg wires. 4 high mod keeps low beams on with high beams. Made with all new materials, all connections crimped and soldered, ceramic headlight plugs, 30 amp inline fuses, 4 relay block with moveable...

www.gmt400.com