Maybe someone hear has a answer rear lights not working.

When I posted this I thought you were taking about the back up light. I blame it on bourbon at 4 am.

For turn signal and brake lights it's a little more complicated, assuming your front and side signals/markers are working start at the fuse panel and relays. Then go to the rear and stay working your way back up. Chasing down a short is a time consuming process. A quick fix for now is to go get a 4 wire harness from Walmart or autozone to run from the cab side light cord plug and run it back to to the rear of the tractor.

 

Which light cord plug are you talking about, not the trailer 7 way I assume?

 

Yes the trailer 7 way. But on the tractor socket of the plug. Not what I would call "fixed" but works till you get home and can be climbing under the truck in 70 degree weather vs 5 degrees and laying in slush. Left turn/right turn/brake/tail light perfect fir a 4 wire harness. Use the existing ground stud at the rear of the frame.

 

I have never been able to have both brake lights and turn signals off of the 7 way. I pulled a boat trailer back from Florida I bought once. I used the 7 way, but just hooked up the turn signals and brake wires, used the bright for turn iirc, and then some magnetic lights for tail lights.
I was pulled in for inspection with this get up not too long after I got on the road and nothing was mentioned over it.

 

You just got to splice in to the right prong on the 7way. I don't have a chart in front of me so I can't give the right position for them at this moment, but a 7 way is going to have
1 abs (it's the center pin , on older trucks before abs it was an extra to use for whatever you wanted such as dump valve)
2 clearance lights
3 tail lights
4 left turn
5 right turn
6 brake
7 ground.
Use the truck frame for ground, so an easily aquired 4 wire harness can be used for left/right turn, brake, tail. Obviously back at the truck lights you will need to use the tail and brake for both lights.

 

I have tried that, and it doesn't work, when you use both the brake wires and the turnsignal wires on the same wire on the bulb. Not saying you won't be able to get home, but when you apply brakes it messes with the turn signals, because it is giving currant to both sides.

 

Right. It's a fix to get home, not a permanent fix