Troubleshooting Running Light Circuit of Curt Trailer Wiring # C56673 Not Functioning

Published 10/11/2018

Question:

I connected the wiring harness to the factory connection on my 2006 Ford Freestar, installed the relays and fuses and then connected the trailer. The running lights did not work, all of the lights flashed when the right turn signal was operated, and both brake lights flashed when the left turn signal was on. Thinking it may be a trailer issue, I connected a set of towing lights to the 4-pole plug and got the same results. This time, when I turned on the running lights, it blew the 20-amp fuse installed near the front of the fuse box. I have traced the wire on the van as far as I can to see if there is a short, but none was visible. I am out of possibilities of the cause of this condition. Your help would be greatly appreciated.

asked by: Jeffrey D

Expert Reply:

Have you tried swapping the relays of the Curt # C56673 around that you installed with the harness? Easiest way to determine if a relay is blown is to replace it with a known working one. A short on your trailer wiring could have possibly damaged it or it was defective.

expert reply by: Jameson C