I have a trailer brake wiring problem. My 04 Ram 1500 had a factory 4 pin hookup. I needed a 7 so I used the factory plug in under the dash for the trailer brake controller. Herein lies the problem, with the brake controller plugged in I get no reaction when applying the foot brake. I can use the manual slide and the brakes on the trailer work fine. I am using the white with brown stripe factory wire as the cold side of the brake light switch as directed. However there seems to be no voltage there when the brake is applied and I have checked that the wire actually runs to the brake light switch. I pulled a tailight and found there was no matching wire in the light cluster but when the brake was applied I had power on a green with white stripe wire. I found this wire at the brake light switch and tapped into that, this results in blown fuses for the trailer brakes. The white with brown stripe seems to terminate at the rear of the truck and connect to nothing but has a factory termination end on it. I am at my wits end and have tried three different controllers and all have the same result. This all occurs whether hooked to a trailer or not. Am I using the correct wire for the cold side of the brakelight switch? Can somebody pledase help? I have wired many trucks for brake controllers in the past and never seen this problem, have even tried to wire around the factory plug and still have the same results. Would really appreciate any insight to this dilema.

 

Turned out that the CHMSL circuit was the problem. Never dreamed that the 3rd brake light would be in the loop for the trailer brake activation. Oh well, fixed now.

 

curiously what is that you did to fix this problem... I may run into it myself.