Brake Light Switch: Description and Operation

The stoplight switch not only provides power to the stoplamps, it also provides a signal to various other systems including:
- anti-lock brake control module
- Powertrain Control Module (PCM)
- shift lock actuator
- speed control servo

Power is provided to the stoplight switch through Fuse 7 (15A) in fuse junction panel. This fuse is hot at all times. With the stoplight switch closed, power is provided to the stoplamps. Ground is provided to the stoplamps through Circuit 57 (BK).