Trailer Wiring Mess

[ReelSlim]

Given all the information that you have provided, I would suspect the trailer ground is the problem. An easy way to check is to run a wire from the ground on the truck. Ensure it is grounded to the truck, activate the light you want then go to the back of the trailer and touch the ground wire to the bolts that hold your light on the trailer. If you get the correct light with this, the ground on the trailer is the issue.

I have found that most light issues are ground problems with trailers.

Hope this helps

X2 Phil.............this is the easiest and quickest way to determine whether the problem is the trailer ground which it most likely is or on the truck end. I usually end up running a seperate dedicated ground wire from the wiring harness to each tail light bolt and it makes for a more reliable connection over the long haul.......IMO Good Luck......

 

[vanisland]

Well back to pulling my hair out trying to figure this out. I pretty much gave up and took the truck to uhaul, where they plugged in there tester and found the same thing I already know. So they said they could replace the convertor box again, which is new and that's pretty much it. Otherwise I would have to pay them to spend hours looking for the problem on the truck. Not much help there. I did just try another new convertor and still the same thing. I just don't understand how the truck lights can work perfectly, the convertor is working and wired properly but still have problems. Anyone know anyone whos good with vehicle electrical or know a good place to take it? Thanks