See Figures 1, 2 and 3
Cruise control is a speed control system that maintains a desired vehicle speed under normal driving conditions. However, steep grades up or down may cause variations in the selected speeds. On these vehicles, the speed control system is electrically controlled and vacuum operated. The electronic control is integrated in the Powertrain Control Module (PCM), located in the engine compartment.
The main parts of the cruise control system are the functional control switches, speed control servo, servo cable, Powertrain Control Module (PCM), vacuum reservoir and the release switches, including the dual function brake light switch.
The cruise control module assembly contains a low speed limit which will prevent system engagement below 30 mph (50 km/h). The module is controlled by the functional switches located on a lever on the steering column or steering wheel and on the instrument panel.
The release switches are mounted on the brake/clutch/accelerator pedal bracket. When the brake or clutch pedal is depressed, the cruise control system is electrically disengaged and the throttle is returned to the idle position.