No Trailer Lights Using a 4- to 7-Way Adapter

Question:

Ive got everything hooked up and double checked everything. I plugged my 7 pin adapter into the 4 pin of this harness and plugged in a light checker. Went through brakes and signals with no indicators at all. Im at a total loss. This is my second install and I had no problem the first time. ps does it matter if the ground from the 7 pin is ground or not?

asked by: Mike

Expert Reply:

Yes, it will matter if the ground wire is attached. It will have to be attached to a clean, bare metal surface or the 4- to 7-Way adapter will not work. It sounds like that is the problem. Especially if the 4-Way by itself has power but does not when plugged into the adapter.

expert reply by: Michael H