Troubleshooting Trailer Wiring that Stops Working When Coupler Attaches to Hitch Ball

Question:

I have a ground wire system on my boat trailer. When the trailer is on the hitch, the lights dont work. If I take the trailer off of the hitch and plug in the lights, all the lights work. Im thinking I have an obvious grounding issue but not sure where. Any ideas?

asked by: Rob S

Expert Reply:

Sounds like there's a short to the frame of your truck or on your trailer which is causing the ground circuit of your trailer wiring to short out when connected.

So what I would do is use a circuit tester like the # PTW2993 to test the hitch for voltage by probing it and then also the frame of the trailer when connected. Either way you are going to need to find a circuit that is shorting out to the frame of the vehicle or the trailer and fix as needed. Typically this is exposed or cut wire touching the frame.

expert reply by: Jameson C