Tail lights and running lights wont work
 

Headlights, blinkers, and break lights all work. They should come on when i pull the headlight switch out to the first click but I get nothing. I even replaced the headlight switch checked fuses and wiring. Any ideas???

1985 GMC Jimmy.

I had a similar problem in a 94 full size blazer. I had no right brake light or turn signal. After testing all the wiring and where I should have power but didn't from the back and did the same thing from the front and firewall. Found a broken wire in the bundle that goes back there around the driver side front fender. It had rubbed against fender and cut it in 2. Might track the wire down from the wires to the switch and see.

After searching the forum I came across this pic of the light switch. On mine the brown and orange wires are cut. According to this thread the brown wire is tail lights and the orange is the front running lights. Guess I got some work ahead of me.
http://i344.photobucket.com/albums/p...bfd/lights.jpg

The brown wire should be the park lights. The orange wire looks to be the main power for the park lights from the schematic I have, but it does not clearly show where it comes from.

Thanks for the help