just replace the brake light switch on the pedel under the dash. dont pull the pin in the new one tell you install it on the car or it will break it.

 

Yall probably know this but there are separate fuses for these lights. My brake controller didnt work and it was due to my CHMSL (Central High Mounted Stop Light) 10 Amp fuse... If I had looked at the back of the truck I would have seen that the over head brake light was out and I would have changed that fuse and my brake control would have kept working. So the lesson is: There was a fuse for the Left and right brake and turn signals but there is also a 3rd fuse for the over heard aka 3rd brake light. If that is out your brake control wont fully function either....