Switch - Stop Lamp: Operation

WARNING: This page is about a different car, the 2006 Dodge Magnum, 2006 Dodge Charger, and 2006 Chrysler 300. However, it is still accessible from the selected car via links, so may be relevant.

The stop lamp switch has three internal switches used for various functions. Among these are:

Brake lamp actuation
Speed control deactivation, and
Brake sense for ABS and brake transmission shift interlock

When the brake pedal is in the released position, the plunger on the outside of the stop lamp switch is pushed inward by the brake pedal. In this position, the electrical contacts for one internal switch are open while the electrical contacts for other two internal switches are closed.

When the brake pedal is pressed, the plunger on the outside of the stop lamp switch extends outward. This action closes the electrical contacts for the one internal switch and opens the contacts for the remaining two switches within the stop lamp switch. The internal switch which closes when the brake pedal is pressed completes the circuit to the brake lamps at the rear of the vehicle, thus allowing illumination of the brake lamps and the center-high-mounted stop lamp (CHMSL).