2015 F 250 Trailer Wiring Diagram. It does seem like a strange problem, but something similar happened to me when I wired my trailer a little loosely on the connectors. Here is the wiring diagram for the trailer wiring for your truck.
Not sure which wires attach to what on your trailer connectors? Visually checked every fuse and found no problems there. It shows the elements of the circuit as simplified forms, and the power and also signal links between the tools.
Check out or trailer wiring diagrams for a quick reference on trailer wiring.
Now to return the thing and try to find the correct one.
I have recently lost my running tail lights and licence plate lamps. The wires that run through the firewall are 'customer access' wires (firewall pass through) and aren't for the brake controller. Rewiring a trailer involves removing the old wiring and trailer lights, routing the new wiring harness through the trailer frame, installing new trailer On a piece of paper, create a simple sketch of your trailer like the one pictured here.