
Stop lights are red lights fitted to the rear of the vehicle. They are usually incorporated in the taillight cluster although many vehicles have a higher additional stop light mounted on top of the boot lid or on the rear window called a high-level stop lamp.
The stop lights are activated whenever the driver operates the foot brake to slow or to stop the vehicle.
The circuit consists of:
When the operator of the vehicle depresses the brake pedal, a switch mounted on the pedal support is closed. This allows electrical current to flow from the battery through the fuse, through the switch, to the brake light filaments and to return to the battery by the ground system.
When the driver releases the pedal, it returns to the rest position and open circuits the stoplight circuit. The flow of electrical current stops and the brake lamps are extinguished.