Troubleshooting Trailer Brake and Turn Signal Lamps

Question:

2009 Dodge 1500 Laramie I rewired the trailer fresh lines, LED light box, with in unit ground lines. I built new mounting brackets with fresh steel, wire wheel scrubbed the mounting area for the bracket down to steel. I am using a 7 to 4 adapter, due to 4 to 4 not working at all. The adapter has test lights and all respond to turns and brakes, as well as markers. Still no brakes or turns. Please help.

asked by: Timothy B

Expert Reply:

What you describe still sounds like it might be a ground problem.

I'd make sure the adapter you used on the vehicle is securely grounded to the vehicle with good attachment to clean metal. Check the main ground on the trailer tongue, which is where the main ground from the trailer connector should attach, make sure this connection is also secure and not corroded. I like to install a star washer on my ground connections between the ring terminal and the trailer frame to get a good bite into the metal for a reliable connection.

Does your trailer have a folding tongue or a tilt bed? Over time the hinge at these locations can wear to the degree that they no longer provide a continuous ground connection. If that's the case, use a length of wire with a ring terminal on each end to join the moving and stationary position of the trailer to make a continuous ground connection.

expert reply by: Mike L