Ford E450 brake Controller wiring problem
I am new to RVing trying to figure out the under dash connections for a Hayes controller. I read the posts about Ford's plug hidden behind the coin holder. Found it. Can I splice the four controller wires into it and have trailer brakes or should I try to find a way to wire into the four wire bundle under dash labeled connect brake controller here. The problem with the latter is the black wire is supposed to be powered and it is not?