Need Help Troubleshooting Tail Light Issue

Hi Everyone,

I bought an old 98 W900 a couple of months back. I've been doing a lot of work to it on my spare time but I have to have her out on the road this next week. Everything is running great except a couple of small issues.

The guy I bought the truck from did some sub-par wiring work on the truck.

I can't seem to figure out why my tail lights wont work. My brake lights and turn signals work fine. My upper marking lights and headlights work as well. But my marker lights under each door do not work and my tail lights don't work.

I've attached a few pictures with notes in hopes someone can tell me which wires are not wired correctly.... or better yet, which wire on the rear of the truck is for the tail lights.

PS I'm not very good at troubleshooting electrical.

 

I think you guys are 100% right. Starting over with fresh wire would be the best idea. I tried grounding out the black wire and nothing happened. This guy did not color coordinate his wires at all which makes troubleshooting that much harder.

Does anyone have an idea where I could tap a wire to get the tail light/running light signal?

My only working running lights are on roof so I can't easily tap there. I suppose I could run a wire straight off the panel from the parking light fuse.

I'll be running during the day this week so I could make it without tail lights as long as I don't get hit with a DOT inspection.

 

I had to go pick up a trailer I bought today (they were going to charge me for storage if I waited any longer). Still no luck on getting my tractor tail lights going but my trailer tails are working. Unfortunately, my warning cluster decided to stop working too and that caused my low pressure warning to not work.

Took the back way home and sure enough.... at the last 10 miles of my 300 mile trip...a random DOT checkpoint!!! As I pulled in I knew I was going to get put out of service.... Then the guys waive me through... I guess they clock out at 5PM ... I lucked out.