09 F-150 trailer brake problem

i had a topper installed last week and they tapped into a purple wire on the brake pressure sensor (i believe) to power the third brake light on the topper. but now my trailer brakes don't work, the controller will turn on at start up but won't stay on. i have read that this controller senses the brake pressure and the brake advancement from the wheel speed and the pressure in the brake line. but shouldn't the controller kick on with the manual switch?? checked all fuses, disconnected the topper, and still nothing, i hooked up the trailer to a different truck so i know the trailer works. thanks for any help.

Take it back and bitch!

bitch----NICELY

bitch----NICELY
Oh yah,.....nicely!