1991 K1500 - Rear Lights Wiring?

thisflatearth · April 25, 2011

My father in law was trying to be a hero with his 230,000 mile 1991 K1500 GMC and his hitch ripped off the back of the truckwhile trying to pull out a small decorative bush that I managed to get out in 15 minutes with a spade shovel.

In the process he ripped the trailer harness out and has disabled the brakes/reverse/blinker wiringand its all just kind of hanging down there.

I am trying to fix it now with the touch and go method. Its been pretty slow. Was just wondering if there was a link that I couldn't find on the interwebs for the color coding. And to make the thread complete here is a crappy phone pic of the outcome.

gregrocks89 · May 3, 2011

The last trailer plug i installed there was a wiring diagram on the back for what should be hooked up to which wire.

mjlimo82 · May 4, 2011

My 7 pin harness fell off during a fuel pump swap and took the lights and such with it, so I know what you're dealing with. The colors on the truck are very similar (if not the same) as a trailer wiring kit's are, or at least on my 90 that is nearly identical to your 91 it is. My harness was butchered to put the trailer lights in rather than someone using the kit, so what I did was cut the plug completely off and used standard 14 gauge wire to lengthen what was already there, then secured the two wires together (truck end and taillight harness end) with industrial wire nuts (the good ones, not cheapies) and secured all of it with electrical tape. Have not had one problem. If I can remember to do so, I'll take some pictures of mine and show you what I did and the colors and maybe that'll help you get this one back together.

I sure don't like having done it that way, but it was the only way I could get them working and it may be the same case for you. But, like I said, I've not had any problems with it at all so I can't complain too much. It was very easy wiring a 4 pin trailer harness back in too.