Parking Brake Warning Switch: Description and Operation

The brake system indicator light comes ON to alert the driver that the parking brake is applied, or that the brake fluid level is low. It also comes ON as a bulb test when the engine is cranked.

Parking Brake
With the ignition switch in ON (II) or START (III), voltage is applied through fuse 15 to the brake system light. When you apply the parking brake, the switch closes and provides a ground for the light. The light then comes ON to remind you that the parking brake is applied.