Trailer Lights Not Working with 2011 Ford F-350 After Trailer Light Burned Out

Updated 08/03/2015 | Published 08/02/2015

Question:

I have a 2011 f350 with factory installed 4/7 pin trailer connector. I had a light on my trailer burn out and ever since then the trailer turn,brake and emergency lights dont work. When the trailer is connected and I open my door or turn on the lights, I have lights on the trailer, but nothing else. I have checked all the fuses in the fuse box and relays under the hood and they all look good. I have a buddy that we plugged the trailer into his 7 pin connector and everything works fine so I know its not the trailer. When I check the 7 pin connector with a test light I have power to the main terminal and running light terminal, but nothing to L/R terminals when blinkers are on. Dont understand it. Everything was working fine on the last camping trip, but ever since the trailer light burned out, everything has stopped working. Ive taken out fuses, switched relays and checked all connections. Is there something Im missing?

asked by: Doug

Expert Reply:

Up until you said you switched relays I was thinking relay the whole time. But if using a good relay in place of a potential bad one didn't solve the problem and the fuses are all good then that could only mean there is a problem with the actual wiring somewhere between the front of the truck and the trailer connector.

Trace the wiring all the way back to front and look for and repair any damage to the wiring.

I assume the truck turn signals work fine but if they don't make sure the flasher is still working. That's the thing that makes the clicking noise when the turn signals are on. Also make sure the stop light/CHMSL fuses are good.

expert reply by: Michael H