Operation CHARM: Car repair manuals for everyone.

Brake Signal: Description and Operation



Brake Pressure Applied Switch

F-250/550 and E-Series:





F-650/750 With Hydraulic Brakes:





F-650/750 With Air Brakes:






NOTE: The Brake Pressure Applied switch is present on vehicles equipped with speed control.

All vehicles with hydraulic brakes have a single brake pressure (BP) switch. An air brake equipped F-650/750 vehicle has two BP switches. A BP switch provides a backup for the Brake Pedal Position (BPP) switch. Normally, a brakes-applied signal from the BPP switch will disengage the speed control. If the BPP switch signal is lost, the BP switch will then supply the brakes-applied signal to the speed control servo.