Electro-Motor Cruise Control

Fig. 1 Cruise control module:

The Electro-Motor Cruise Control System is used on 1988 C and K Series trucks. The system enables the operator to maintain a selected vehicle speed under normal driving conditions. Capabilities of the system include cruise, coast, resume speed, accelerate, tap-up and tap-down. Basic components of the cruise control system are the cruise control module, mode control switches, electrical release switches and related electrical wiring.
The cruise control module, Fig. 1, houses an electronic controller and an electric motor. The controller monitors vehicle speed and operates the motor accordingly. Desired cruise speed is maintained as the motor moves a connecting strap and throttle linkage. A low speed limit in the module prevents engagement of the system at vehicle speeds below 25 m.p.h.. Controller operation is varied by mode control switches on the turn signal lever.
Electrical release switches are used to disengage the cruise control system. Two release switches are located on the brake pedal bracket and, on manual transmission models, an additional switch is mounted on the clutch pedal bracket. When the clutch or brake pedal is depressed, the cruise control system is disengaged and the throttle returns to idle.