Questions and Answers

GMC S15 Jimmy Flashing Brake Light Q. 1989 GMC S15 Jimmy. Brake warning light is flashing constantly. Brake lights don't work. Emergency flashers don't work. Turn signals work fine. I have replaced the brake light fuse, brake light switch, flasher, and bulbs. I also topped off the brake fluid. Do you have any suggestions?

A. There are two different flashers on this car. One for turn signals and one for hazards. Make sure both are okay. The brake light circuits go through the turn signal switch as well to get to the rear bulbs. Make sure you don't have a problem in the turn signals switch.

The flashing red brake light is most likely a problem in the Rear Wheel Anti-lock Brakes System(RABS). You need to diagnose this with a service manual and a scan tool so you can retrieve any trouble codes from the module and see where that leads you.