Installing a 7-Way and Brake Controller on a 2003 Dodge Ram 2500 that Has a Factory 4-Way

Question:

Ive located the factory plug for the brake controller under the dash however cannot find any such wires at the back bumper. I have a factory 4 pin back there but not the others I need to complete the 7 pin install should I abandon the factory wiring and just run all new stuff. Or is there a secret Im unaware of. Thank you for taking the time.

asked by: Wes

Helpful Expert Reply:

To install a 7-Way on your 2003 Dodge Ram 2500 that has the factory 4-Way you will need # ETBC7 because part of it will have to be hardwired. Or, instead of the whole ETBC7 kit you could use just # 37185 and enough # 10-2-1 to reach from the back to the front of the truck (about 25 feet is what I would use, sold by the foot), and a 40 amp circuit breaker # PK54540.

Your 4-Way will plug into the 7-Way. The white wire will get grounded to the truck frame. The black wire will ultimately connect to the positive battery terminal via the 40 amp circuit breaker. Blue will ultimately connect to the blue output wire at the back of the controller so you would remove that blue wire from the end of the harness that plugs into the truck.

That just leaves the purple wire which is only needed if the trailer has reverse lights. If it does then it splices into a reverse light wire at the back of the truck. I have included some links that will help. Not all of the information pertains to your situation so just follow the relevant parts.

expert reply by: Michael H