How to Wire a Brake Controller on a Toyota Sienna 2005 XLE

Expert Reply:

You will need a Wiring Harness, item # 118304, to start with. Once you have this wiring harness installed and working properly you will need to do some additional wiring to complete a 7-Way connection at the rear of the vehicle. You will need the Brake Controller 7 & 4 Way Installation Kit, item # ETBC7. This kit comes with all of the wiring, brackets, circuit breakers and connectors needed to complete the installation of a brake controller and a 7-Way connector.

To complete the wiring at the rear you will need to run one wire from the blue wire on the 7-Way to the brake controller and one wire from the black wire to the vehicle battery through a 40 amp circuit breaker. These wires need to be routed along the underside of the vehicle, avoiding pinch points, moving parts and sharp edges, to the engine compartment and one of the wires needs to be ran into the passenger compartment through the fire wall along with a power wire and ground wire for a brake controller. Use the included zip ties to secure the wiring as you go. Each vehicle presents different challenges for routing of the wiring so there is not a best path that can be easily explained.

Once you have all of the wiring routed you will need to install a brake controller. The Tekonsha P-3 Brake Controller, item # 90185, is a good choice. To install the controller you will need to use a circuit tester, item # 3808, to find the brake switch wire that goes hot only when the brake pedal is depressed. This wire is located under the dash behind the brake pedal switch. Once you have this wire located connect the red wire from the brake controller to it. Next connect the ground wire to the white wire on the brake controller, the power wire to the black wire on the brake controller and the brake feed wire from the 7-Way connector to the blue wire on the brake controller. Mount the brake controller to an easily accessible but out of the way place and you are finished. Check out the brake controller installation link below for detailed installation information.

expert reply by: Bob G