Maddening issue replacing wiring harness

Like others on here, I'm sure, I tore off the 7-pin factory wiring harness by catching it on a stump. Wired up replacement, very straightforward, just matching up the wiring colors.

But something is not right. Right turn signal lights up every light on the trailer. Brake lights illuminate every light on trailer, including side markers. Left turn does not work at all. Only one tail light works on the trailer.

Hooked up to different trailer -- same issue. Swapped out harness and just wired up a 4-way flat, using only ground, green, yellow, brown from truck's factory wiring -- same issue.

It's acting like a loose ground, but I can't find it. Or, could the relay be bad?

Any advice would be greatly appreciated.

Jim

2011 4WD

 

When you test the truck outputs with a DVM, doesn't it match up with what you see on the trailer?

If yes, seems like you'd have to go back further in the harness to find where the probable pinch/cross short is. It may be visually hard to find, but I'll bet it's there.

 

Bill:

Yes, DVM is showing the same thing I saw on both trailers.

Jim