Locating Cold Side of Brake Stoplight Switch to Install Brake Controller on 2007 Lexus RX 400h

Question:

Cant find the brake wire to tie the red lead from an Activator 4-wire brake controller. There is a 4-wire connector on the right side of the brake pedal, but when disconnected the brake light still operated. Where can I find the correct wire for this connection.

asked by: Eric

Expert Reply:

According to my contact in the Tech Services department at Tekonsha, you are looking for a blue wire coming off of the brake stoplight switch located on the top of the brake pedal. Simply follow the brake pedal up under the dash, you should find the switch attached to the upper portion of the pedal.

You can confirm this by using a circuit tester like part # PTW2993 on the wire. The wire should only show power when the brake pedal is applied, not with the turn signals, headlights, etc.

I have linked you to some articles that you might find helpful.

expert reply by: Mike L