Cruise Control: Description and Operation

Cruise System Schematic:

MAIN SWITCH
Main switch has a holding type circuit. When turned "ON" with ignition "ON," A.S.C.D. relay is energized, supplying power to the system. Although main switch automatically returns to its original position, relay remains "ON." When ignition is turned "OFF," relay is de-energized and remains inoperative until main switch is turned "ON" with ignition "ON."

COAST SWITCH
Has an "ON-OFF" type circuit. When switch is depressed, CRUISE lamp illuminates. With switch depressed, controller cancels preset speed. Controller will preset speed at which vehicle is moving when switch is released.

ACCELERATE AND RESUME SWITCH
Increases set speed or returns vehicle to speed set before system cancellation by depressing brake pedal, etc. Pressing ACCEL end of switch causes vehicle speed to increase; releasing switch sets system at speed vehicle is moving. Pressing and releasing RESUME end of switch causes vehicle to automatically return to speed set before system cancellation by depressing brake pedal, etc. Keeping RESUME end depressed causes vehicle speed to decrease.

SPEED SENSOR
An "ON-OFF" type switch, located in speedometer, generating two pulses per meter cable revolution.

SERVO VALVE (TRANSDUCER)
Causes vacuum valve and atmospheric valve to open or close according to input current and adjust vacuum from intake manifold.

CONTROLLER
Compares preset speed with actual vehicle speed, maintaining preset speed by increasing or decreasing current flow through servo valve.

RELEASE VALVE
Safety valve that shuts off vacuum line atmospheric passage when system activates.

ACTUATOR
Moves the throttle with vacuum supplied by servo valve.

STOP SWITCH
Used to release system. When brake pedal is depressed, switch cuts power to system circuit.

STOP LAMP SWITCH
Operates stop lamps. Signal from this circuit is also sent to controller, causing it to cancel speed control system.

INHIBITOR RELAY
Cancels system when gear selector is set to "N" or "P."