Originally Posted by m.i.k.e.
I tested it with a multimeter and got nothing at the brake pin. Every other pin works fine but no power at the brake one.
There won't be any juice at the trailer brake pin in the plug unless someone is stepping on the brake pedal while you check the pin.
Next step is to double check that you plugged the fuse and relay into the correct holes in the power distribution box under the hood. Use the fuse diagram in your Owner's Guide to see which places the fuse and relay should be plugged into. The relay doesn't matter as it is for parking lights. But there are three different fuses that can affect trailer brakes:
Under the dash in the fuse box:
-- 10-amp mini fuse in #37 for trailer brake control.
Under the hood in the power distribution box:
-- 30-amp cartridge fuse in #17 for trailer brake control
-- 10-amp mini fuse in #46 for brake on/off. Ford installed that one, but it may be blown out