Cruise Control: Description and Operation

This speed control system is electrically controlled and vacuum operated. The speed control module stores the exact speed of the vehicle the moment the set button is pressed and released. This system adjusts the throttle position eight times per second to hold vehicle speed within one mph of the speed set.
This system uses a vacuum reservoir to maintain the set speed when climbing a hill. The rapid deceleration cutoff is used to turn off the system if vehicle speed drops by more than 10 mph even if there is no indication that the brakes have been applied. The wheelspin cutoff will turn the system off if the set, resume, brake or clutch switches do not close and reopen when activated or if a wiring malfunction occurs in these circuits. This prevents the system from operating in an unexpected manner because of a system malfunction.