1. Stop light switch
2. Brake warning light switch 1. Stoplight Switch It is a spring-loaded electrical switch that operates the rear stoplights of the car. Most modern cars use a mechanical switch n the brake pedal mechanism. The switch is normally open when the brake pedal is depressed; it closes the switch and turns on the brake lights. Hydraulically operated stoplight switches are used on some older cars. Brake system pressure pushed on a switch diaphragm and close the switch to operate the brake lights. 2. Brake Warning Light Switch It is a also called as pressure differential valve, warns the driver of a a pressure loss on one side of a dual brake system. If a backs develops in either the primary or secondary brake system in equal pressure acts on each side of he warning light switch piston. This pushes the piston to one side, grounding the indicator.