Ok, heres the deal. I bought a used, (1992) F-250. The guy had used it to pull a fifth wheel travel trailer, thus it has a brake controller/plug in. The only problem is the plug in for the trailer brakes is in the box, because it was fifth wheel trailer. I need to be able to have the plug in at the back bumper so i can plug my landscape trailer brakes into it. My question, can i splice into the existing wire and run it to the back bumper and put another plug on it?