Checking the brake signals

The operation of the brake lights is best checked with an assistant. Step on the brake with your foot while the assistant checks to see if the lights come on. You can check the brake signals without assistance: place the car with its back to the garage door and press the brake pedal with your foot. The red light of the lamp will reflect off the garage door. If any lamp does not light up, replace the incandescent lamp; if both lights do not come on, the brake light switch may be faulty.