D 250 Pickup V6-239 3.9L (1989)
Cruise Control Module: Testing and Inspection
Fig. 5 Engine Controller 60-Way Connector, Shown From Terminal End
1. Set voltmeter to read 12 volts, then connect negative lead to chassis ground.
2. Connect positive lead to pin 7 of module connector then drive vehicle at speeds between 40 - 50 mph.
3. Turn speed control switch to the On position. Voltmeter should read 12 volts.
4. Press and release the speed control Set button. The voltmeter should indicate from 5 - 9 volts and fluctuate 1 - 2 volts at a rapid rate.
5. Speed control system should be performing throttle control at this time, maintaining set speed. If not, replace control module.
