Cruise Control: Description and Operation

The Speed Control System is powered by the 15A Fuse 11 of the Interior Fuse Panel and is hot with the Ignition Switch in the ACCY or RUN position.

The Speed Control Amplifier controls vacuum to the Speed Control Servo Motor through the modulating valve. The Servo Motor moves the throttle through the actuator cable.

To operate the Speed Control System, the engine must be running and the vehicle speed must be faster than 30 m.p.h.. The system is put into standby mode by pressing the ON switch of the Speed Control Switch.

Pressing and releasing SET/ACCEL or COAST sends a command to hold the present speed. Note: The speed control will not hold speed when the SET/ACCEL or COAST button is pushed, unless the ON button is pushed first. The Speed Sensor (at the transmission) sends signals to the Speed Control Amplifier. These signals tell the amplifier to increase or decrease the vacuum at the Servo Motor to keep the vehicle at the set speed.

Pressing and holding SET/ACCEL speeds the vehicle up. The vehicle speed increases as long as SET/ACCEL gives the system a new set speed to maintain. Vehicle speed may also e increased by depressing the accelerator until the higher speed is reached, and then pressing and releasing SET/ACCEL.

Pressing and holding COAST slows the vehicle down. The vehicle speed decreases as long as COAST is depressed. Releasing COAST gives the system a new speed to maintain.

Pressing OFF or turning the Ignition Switch to the OFF position turns the system off (set speed not maintained). The system returns to standby mode when the brake pedal is depressed. The Vacuum Dump Valve also operates when the brake pedal is depressed. This is a backup device which relaxes the servo. In vehicles with manual transmission, the Clutch Switch opens when the clutch is depressed and returns the system to standby mode also.

When the system has been deactivated by depressing the brake or clutch pedal, the last set speed may be resumed by pressing RESUME.

This feature will not work if OFF has been depressed or if vehicle speed is below 30 m.p.h. or if the Ignition Switch has been turned OFF since the speed was set.