How Does Brake Controller Install in 2008 Lexus GX 470

Updated 07/16/2019 | Published 07/15/2019

Products Featured in This Question

Draw-Tite Activator IV Trailer Brake Controller - Up to 4 Axles - Time Delayed

(357)

$103.67

Tekonsha Plug-In Wiring Adapter for Electric Brake Controllers - Toyota and Lexus

(1399)

$21.07

Tekonsha Prodigy P3 Trailer Brake Controller - 1 to 4 Axles - Proportional

(6648)

$165.67

Hook Probe Circuit Tester

(60)

$13.03

Question:

Hi- I need help wiring my Tekonsha P3 wiring 4 wiresto the Lexus OEM harness. 2008 GX470. The oem has 5 wires black, white w long black stripe, yellow, green, green/silver loop stripes. Thanks

asked by: Steve O

Expert Reply:

To install the Prodigy P3 part # 90195 in your 2008 Lexus GX 470 that has a factory 7-way you'd only need the install harness part # 3040-P which plugs into the port under the dash of the vehicle.

If instead you wanted to hardwire the controller to the wiring you have now you'd need to run the black wire of the P3 to the wire that has voltage all the time (you'll need a circuit tester part # PTW2993 for this), the red wire runs to the wire that has voltage only when the brakes are applied.

Ground the tester to the constant 12-volt power wire, then probe the remaining two wires. The wire that lights the tester will be the ground (runs to white), the other will be the brake output circuit (blue wire).

expert reply by: Jameson C