Brake Controller Wiring on a 2008 Jeep Grand Cherokee with Factory Installed 7-Way

Expert Reply:

Hi Steve. Do you have any pre existing wiring at the back of your Grand Cherokee, (4-pole or 7-way)?

expert reply by: Amanda

Expert Reply:

Thank you. The Grand Cherokee does not have a quick plug in under the dash, but since you have the factory installed 7-way, a lot of the work has been done for you. You have four wires coming off of the brake controller, red, blue, black and white. On the driver side, down buy your feet, off to the left and under the mat, there is a light blue wire that should be labeled brake. I spoke with my installer about your vehicle and he said the hardest part is finding that wire. He said sometimes it seems impossible to find, but it is there. Once you find this wire, it will connect to the blue wire on your brake controller. Behind the brake pedal, you will need to find the the stop light switch. You will likely need to use a circuit tester to test the wires until you find the correct one. You will connect the red wire from the brake controller to this wire. The remaining to wires will need to go through the firewall to the battery of your Jeep. You will need two 10 gauge wires. (You could use part number 10-2-1) The black wire on the brake controller will need to be connected to the positive on the battery, but you will need to put a circuit breaker between the two (usually mounted to the firewall). If your trailer has two axles or less, you will need a 20 amp breaker, part # 9506P. If your trailer has three brake axles or more, you will need a 30 amp breaker, part # 38630. Finally, the white wire on the controller will need to be connected to the negative post on the battery.

expert reply by: Amanda