Exterior lights

[NDFARMER95]

Alright guys I'm new here. Picked up a 96 2500 for a farm pickup and keep miles off my duramax. It needed intake gaskets, replaced those. Now the wiring is a little funny. When I turn the blinkers on without the lights on they flash normal. When I press the break pedal, they start flashing fast and the break lights don't turn on. When I turn the lights on and flip the blinkers on, they blink fast constantly. Press the break and they still don't turn on. While all this is going on, the voltage gauge is bouncing around.

 

[98_k1500]

Sounds like grounding issues, check the ground for the tail lights at the rear of the frame rail (driver's side)

 

[scotttick]

I had one do the exact same thing, it was a ground like mentioned before. Some genius hacked up the harness in the rear while installing a trailer plug.

 

[NDFARMER95]

Okay I tried cleaning what I'm pretty sure is/was ground. It helped me get to where I'm at now. I couldn't get squat to work before. The previous owner hacked the piss out of the harness to install the trailer plug. There's a huge rats nest of wires up under there going to god knows where. Does anybody have a diagram of how it should be done right?

 

[scotttick]

Try this treads website.
http://www.gmt400.com/forum/showthread.php?2910-Lots-of-diagrams

 

[NDFARMER95]

Alright so I got the rats nest out of the back. Is the ground on the frame obvious or am I just stupid? The harness in the back where it t's, There's a bigger white wire and a smaller black one that are just cut and hanging. Is this anything?

 

[scotttick]

http://www.diakom.ru/CAR/GMC/1997/Pickup K1500/SYSTEM WIRING DIAGRAMS/16238.pdf
Shows the complete wiring for the exterior lighting.

 

[98_k1500]

Should be pretty obvious, It grounds on the drivers side frame rail right by where the harness splits to the right/left side.

 

[NDFARMER95]

Sorry guys been busy. Ripped everything apart. I have a bundle of wire the previous owner had ran every which way in the pickup. Tore apart the back harness and the ground was taped up with all the wires and ran in the plastic loom. Grounded it up and boom my lights work awesome.