Troubleshooting Trailer Brakes and Tail Lights Not Working On 2003 Chevrolet Silverado

Question:

Hi, Ordered a Curt 16,000 class five hitch and the plug that uses the factory harness that includes the 7 blade flat and 4 pin connectors. I love them both but one question on my lights now. The taillights on the trailer come on when depressing brake pedal? The controller does not seem to grab now either? It seemed to work fine before, but maybe something was not wired right before? The taillights or running lights don’t come on at all. It seems to be an issue with braking and taillights? Any help is greatly appreciated. Thank you.

asked by: Chris F

Helpful Expert Reply:

I do see you ordered the Curt Trailer Hitch Receiver # C15323 with the 7- and 4-Pole Trailer Connector Socket # HM40975. As your brakes and trailer tail lights previously worked fine but both no longer work it sounds like it is going to be an issue with the brake switch. You should see your brake controller activate when pushing the brake pedal. You can also test the brakes with the manual override. If your controller works only manually you either have a bad switch or fuse/relay. If the controller does not work at all it may be bad or the fuse for it had gone out. Be sure to also check all your fuses/relays for all the trailer lights since you mentioned the running lights also not working.

expert reply by: Bud M