I just picked up a 2000 f350 psd crewcab and it has a wiring issue maybe I could get some insight . The problem is the drivers side windows don’t work, neither does the taillight, or power seat. Please tell me there is a relay or something simple I’ve checked all fuses and they are fine. Relays, the only one that clicks is the automatic roll down relay for the drivers window

 

I feel like you maybe coulda bumped your original thread rather than having 2 threads............
https://www.ford-trucks.com/forums/1...on-t-work.html

I'm not that familiar with the earlier SuperDutys but I fear you might have some time consuming wiring tracing and inspection in your future. You might wanna order or d/l the wiring diagrams for the vehicle. I'd probably start with something simple like the taillight, trace every centimeter from the lamp housing to the front, see if you can get that working. Hopefully that might reveal something along the way.

Couldn't hurt to look at the factory grounding points first. Long shot but easy and free.

 

Check for car it’s and critters....they like the taste of old wiring

 

My 4x4 isn’t working either. Could this be the gem? I have manually locking hubs.

 

My dads 2000 brew cab had the same issue. FINALLY after almost four years I found the problem, the ground wire coming from under the dash going through the door grommet was cut clear in half!!!! Ford made the bundle so short there wasnt enough slack for the wires when ope ing the door and eventually it cut against the cab and SLICE. I added a piece of 12ga wire and soldered it in, EVERYTHING came back on and worked perfect