How to Wire a Third Brake Light on a Truck With Combined Wiring

Updated 12/03/2018 | Published 12/02/2018

Question:

2001 F150 4.6 with 4-way tow adapter. I need to wire cap with some light and third brake light

asked by: Mary

Expert Reply:

Do you have any specific questions that you need help with? The process for installing the interior light will be pretty straight forward. There will be a 12 volt power wire you need to run to the battery with a fuse/circuit breaker and then a ground wire that will need to be attached to a metal surface.

The only not straight forward part of the process is the third brake light power. The tail lights on your 2001 Ford F-150 use a combined system which means the stop and turn signals are on the same circuit. In order to power the third brake light you will need to separate out the brake/turn circuits on the vehicle so the light only illuminates with the brakes. In order to do this you will need to use the Pacer Performance 3rd Brake Light Logic Module part # PP20-702 which I have attached the wiring diagram of for you.

expert reply by: Conner L