Spirit L4-153 2.5L SOHC (1990)
Brake Switch (Cruise Control): Description and Operation
Vehicles equipped with Speed Control have a brake switch that controls three separate
circuits. One circuit controls the power to the brake lights, the other two circuits relate to the Speed Control System as follows:
Servo valve power circuit: Power for the servo comes from the on/off switch and goes through the brake switch to the servo. The switch circuit is
normally closed with the brake not depressed. Either depressing the brake or turning the on/off switch off will open the circuit and cut all power to
the servo.
Brake switch sense: A wire from the on/off switch is connected to cavity no. 29 of the Engine Controller 60-way connector. This wire is what the
controller uses to indicate the on/off status.