Finding the Blue Wire for Trailer Brakes and Brake Controller on a 2008 Dodge Ram 2500

Updated 09/18/2012 | Published 09/16/2012

Products Featured in This Question

Tekonsha Prodigy P2 Trailer Brake Controller - 1 to 4 Axles - Proportional

(2763)

$159.00

10 Gauge Wire - Blue Primary - Per Foot

(104)

$1.84

Hook Probe Circuit Tester

(60)

$12.27

Question:

I have a 2008 ram 2500 that did not come with 7 way hook up in back, I have everything working on 7 way now except brakes where do I splice into the blue wire, I have box plugged in to factory harness but unsure where brake wire is in back, and have read it is probably not in the back maybe dead ended somewhere else? Thank you for your help

asked by: Chad

Expert Reply:

You are correct. Depending on how your 2008 Dodge Ram was factory equipped the wire for brake output could terminate closer to the front of the truck. If it came with a 4-Way and the factory port for the controller, then there is a connector where the wire terminates.

This connector is usually located under the driver's side of the vehicle, right behind the front wheel well. There are more wires on the hood side (right side) of the connector than the hitch side. Using a circuit tester like # PTW2993 if needed you can locate the wire that supplies power to the trailer brakes by having someone apply the manual override on the controller while testing the wires.

Using a quick splice connector, run a wire lead using # 10-1-1 wire, from the blue wire to the back of the vehicle. Enough wire, about 20 feet, will be needed to make it from the front wheel well to the end of the truck bed. The wire lead will connect to the brake output pin on the 7-Way.

I have included a link to an FAQ article that should help with this installation.

expert reply by: Michael H