Installing the Red Wire from Prodigy P3 Brake Controller on a 2018 Subaru Outback Wagon

Question:

Sir, I am installing a Tekonsha P3 brake controller in a 2018 Subaru Outback. Question: Can I connect the “red brake light switch wire” on the brake controller to the brown brake light wire from the converter output at the 7 pin connector instead of the brake light switch wire? Thanks for your help.

asked by: David H

Expert Reply:

Typically the brown wire on a 7-Way carries the running light function. If you were to connect the red wire from the brake controller harness, like what comes with the Tekonsha Prodigy P3 # 90195, then your trailer brakes would be active when you turn your headlights on. Because of this it is best to connect the red wire directly to the stop light circuit by the brake pedal on your 2018 Subaru Outback Wagon. If this happens to be a brown wire then all you need to do is use a circuit tester like part # PTW2991 to verify this. Just be sure it is the cold side that only receives power when your brake pedal is pressed.

expert reply by: Jon G