Installing a 7-Way Trailer Connector and Brake Controller on 2007 Hummer H3

Updated 02/08/2016 | Published 02/06/2016

Products Featured in This Question

Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires

(3395)

$121.25

16-14 Gauge Butt Connector - 5 Pack

(31)

$4.30

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

(2763)

$159.00

Hook Probe Circuit Tester

(60)

$12.27

Question:

I have a 2007 hummer H3 with the adventure and lux package. Unfortunately it did not have the dealer installed tow package. I installed a hidden hitch. It came with a 7/4 wiring. I found the wires for the ground, right, left and running connections in the back. I was unable to find the red or dark blue wires in the rear. I also found the blunt cut wires under the dash to connect a brake controller. I want to finish wiring the 7/4 plug in the rear and add a proportional brake controller in the cab. Can you help me with info on what all I need to do at this point. I am guessing I need to run wires from the engine compartment to the rear but have no clue on where to tie in to use the wires already integrated for a brake controller.

asked by: Bruce S

Expert Reply:

Typically, the brake signal wire and 12V power wire should be in the same bundle of wires where you found the turn signal wires, ground, and running light wires. They may not be blue and black in color, but you can use a circuit tester, # PTW2993, to test for the functions of the wires. You can also use the circuit tester to test the functions of the bundle of wires you found under the dash for the brake controller. Another place the 12V power and brake signal wires may be located is along the driver's side frame rail. Unfortunately I do not know exactly where these wires will be located or what color they may be.

If you cannot find wires for the brake signal and 12V power, you can either take your Hummer to a GM dealer and see if they can locate the wires for you, or you can use an # ETBC7 kit to install a 7-way and 4-way trailer connector and run the wires to the engine and cab for power and brake signal.

To install the # ETBC7 kit, you will first need a 4-way flat connector on your H3, like the Draw-Tite 4-Pole hardwire kit # 18252. You will want to use butt connectors # 05731-5, instead of the included quick splice connectors, to connect the 4-way to the blunt cut wires you found on your vehicle.

The 4- and 7-way connector included in the ETBC7 kit will plug into the # 18252 4-way flat connector. The included duplex wire will run to the engine compartment and cab to provide signal for the trailer brakes and 12V power for the connector. I have attached a help article that outlines the installation of the ETBC7 kit for you.

The brake controller I recommend for you is the Tekonsha Prodigy P2 Trailer Brake Controller # 90885. The Prodigy P2 is a proportional brake controller that offers 3 boost levels to let you adjust braking power and aggressiveness, performs continuous diagnostic checks to alter you to any potential problems, and has an easy-to-read, user friendly LED digital display. I have attached a review video of this controller for you.

Feel free to let me know if you have any further questions.