Truck in question is a '71 Cheyenne. The problems are thus:
1) Headlights on - nothing works on the back. No markers, tail lights, nothing.
2) Brakes - Everything out back will light up dimly. Tail lights, markers, all of it. This happens with lights on or off.
3) Blinkers - Either direction will cause everything to flash dimly. Tail lights, markers, all of it. This happens with lights on or off.
4) The left tail light bulb gets burned up quickly. It takes very little usage before it's no good.
In troubleshooting I tested at the connector where the tail light harness plugs into the main harness. Everything tested properly on the main harness. I went to start looking at the tail light harness and it was such a rats nest that I just yanked all of the wiring and replaced most of it. The pigtails for the tail lights looked okay so I reused them. When I was done everything worked properly, which was just last night. All turn signals, marker lights, tail lights, and brake lights worked fine. After driving the truck around town today it's now back to the same crap. Does this sound like grounding issues? It sure seems like it to me. The lights did all work fine just a month ago, so it is perplexing and I am not sure what else to look at at this point.
