Have a friend with a short in his tail light circuit. I isolated it to be forward of the connector near frame under drivers feet.  Lots of wires there. Where do i find a schematic? The wire is a 14 ga black. I cut it prior to the connector. Spliced the wire going to the rear to a long lead and temporarily ran it to the left headlamp circuit breaker. Wire going forward has a dead short. Overhead council and dash lights are also dead.

Schematic by year are in articles. 

https://mopar1973man.com/cummins/articles.html/24-valve-2nd-generation_50/51_engine/electrical/

 

I was totally off base. The wire i cut was the ground. The schematic really helped. The problem was all rear wiring had no ground. Bad connection at the connector. Put power to tail lights and every filament in the harness would light up. Established the ground and all is better. BUT, Fuse 1 (15amp) panel on left side of dash, (called marker fuse) feeds tail light circuit. With tail and markers on, i pull fuse 1 and they all stay on.  I try the same thing on my truck. Turn on lights, pull fuse, lights stay on. How can this be?  Answer is , i had the wrong schematic. Fuse 1 is not to tail lights.

Edited September 21, 20168 yr by oldbeek
added tet