Troubleshooting Trailer Wiring Circuit that Shorts When Coupler Connects to Hitch Ball

Updated 11/18/2020 | Published 11/16/2020

Question:

My running lights on trailer works fine but second I connect to the ball hitch it blows the running and tail light fuse on truck. Any idea of what’s causing this?

asked by: Jackson

Expert Reply:

You have a short on the trailer wiring that is touching the trailer frame and basically electrifying the frame of it and when it connects to your truck frame it's shorting the circuit since vehicle frames typically are grounded. So essentially it's a short to ground. You need to go over the running light circuit of the trailer wiring looking for any cut or exposed wiring and fix as needed.

expert reply by: Jameson C