Brake Light Switch: Description and Operation

The brake lamp switch is located under the instrument panel at the brake pedal arm (Fig 2). It controls operation of the vehicle's brake lamps. Also, if the vehicle is equipped with speed control, the brake lamp switch will deactivate speed control when the brake pedal is depressed.

When the brake pedal is depressed, the plunger on the outside of the switch extends outward. This action closes the electrical contacts within the switch, completing the circuit to the brake lamps at the rear of the vehicle, thus illuminating the brake lamps and the Center-High-Mounted Stop Lamp (CHMSL).