After Replacing 4-Way Trailer Connector the Trailer Running Lights Do Not Work

Question:

i have a 4-way system and had to replace the male connector. The replacement connector has green,yellow, white and brown but the harness on my trailer has green, yellow, white and two brown wires. I connected the two browns together and all lights work except the running lights.

asked by: Danny T

Expert Reply:

Your trailer has what is called a wishbone harness. This means that it has 2 running light wires (brown), one for each side of the trailer. These harnesses are used so you do not have to run a jumper wire from one side of the trailer to the other to get running lights to both sides.

Since you have connected the 2 brown wires together and are not getting any running lights, I suspect there is a ground problem or a bad connection at the connector on the running light circuit.

Make sure the main trailer connector ground and the grounds for all of the lights are attached to clean and corrosion free bare metal surfaces. If you attached the new 4-Way ground wire to the old ground wire, I recommend instead attaching the new connector ground directly to the trailer frame.

I have included a couple of links that should help you troubleshoot further if needed.

expert reply by: Michael H