Turn Signals On Bumper 7-Way Dont Work but Turn Signals on In-Bed 7-Way Do Work

Question:

I have a 2014 F-350 King Ranch truck. The truck has a combo 7 way and 4 way plug on the bumper and another 7 way plug in the bed from the factory. When I put a trailer on and plug it into the 7 way plug on the bumper the turn signals do not work. Everything else works fine except the turn signals. I went through all the fuses and relays and they are all good. If I plug the trailer into the 7 way plug in the bed everything works fine. My question is do they make a harness that I can replace from the 7 way plug on the bumper to the truck?

asked by: Christopher A

Expert Reply:

I do have a replacement trailer connector for you in the Trailer Connector Socket part # HM40975 but if you need the wiring harness that leads to this plug then you would need to contact the dealer. The in-bed and bumper trailer connectors use the same fuses and relays therefore the issue is going to be most likely where the two harnesses branch off from one another or from that section of wires forward to the bumper 7-way. I recommend that you test the turn signal pins inside the bumper 7-way to see if you are getting power there. If you are then the issue is the trailer side connector but if you are not then test the turn signal wires directly behind the bumper 7-way plug. If you get power then you know the trailer connector is bad but if you still don't get power then you will need to trace this wire back to the point where it ties into the in-bed 7-way.

expert reply by: Conner L