It's been posted at least 4 times by me on 4 different threads on how to obtain a free owners manual within the past two weeks, but I'll guess it's worth repeating again:
I guess I'll create a sticky on this, but it will most likely get passed by there as well.
If it's not the fuse, then check the trailer wiring connector on the lower left hand side of your rear bumper for any possible shorted wiring (doubtful, unless you do have a blown fuse). Also examine the brake switch located near the top of the brake pedal shaft.
Give an answer, they learn for the day; suggest a search, they learn for a lifetime.
2007 F150 STX Supercab (4.6 2V V8), Edge Evolution (87 tow tune), factory navigation radio, tailgate handle backup camera, H-D headlights, Mark VIII 2 speed electric fan conversion with flex-o-lite controller.