Troubleshooting Grounding Issue on Aluminum Trailer

Question:

I have an aluminum utility trailer. All the trailer lights work when plugged in to the vehicle and the trailer is uncoupled. As soon as I set the trailer on the ball it blows a fuse and I lose only running lights. I completely rewired the trailer and still have this problem

asked by: Rob M

Expert Reply:

It sounds like the trailer has a grounding issue. Grounding problems can cause all sorts weird effects and aluminum trailers are notorious for issues with grounding and can sometimes require ground jumper wires.

Often the easiest way to do this is to install a simple junction box like # 38656 where each individual light's ground can be joined and then connected to the main ground that goes to the trailer connector. Ring terminals # 44-5310A are used to make the connections inside the box.

Another way is to join the individual grounds to the one main ground wire using a butt connector like # DW05745-10.

expert reply by: Adam R