Installing a Brake Controller on a 2011 Audi Q5 With a 7-Way Trailer Connector  

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We have everything you need to install a brake controller on your 2011 Audi Q5, but there are no plug-in style wiring harnesses so the brake controller will have to be hard wired. To install a brake controller, you will want our Brake Controller Install Kit, # 5506. This kit comes with a 20 amp and a 30-amp circuit breaker, be sure to check the installation instructions of your brake controller to determine which circuit breaker is required. The 40-amp circuit breaker would only be used if you want to add a battery charge circuit to the trailer connector.

Once you have the install kit, you will need to determine the function of each wire from the brake controller. There should be 4 wires, black, blue, red and white. If your brake controller does not have any wires, then you will want to pick up a wiring harness for your controller. If you can tell me the brand of your brake controller, I would be happy to recommend a universal brake controller harness that will work for you.

Back to the brake controller wires. The black wire is for 12-volt power, and it should be connected directly to the positive terminal of the vehicle's battery. The white wire is ground, and the blue wire is the brake controller output wire that will be ran back to the 7-way trailer connector. To run blue and black wire, you can use the duplex cable that is included in the brake controller wiring kit.

The last wire that you have to connect is the red wire. This wire splices into the cold side of the vehicle stop light switch. The stop light switch is located at the top of the brake pedal arm. You should see several wires coming from the stop light switch. Use a circuit tester like part # PTW2993 and probe each wire to see which wire only has power when the brake pedal is pressed. This is the wire you will use for the red wire from the brake controller.

expert reply by: John H

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