Component Tests - Mechanical Cruise Control

Fig. 3 Engagement switch connector terminals:

ENGAGEMENT SWITCH TEST
Ensure control switch is in the on position during test.
1. Disconnect engagement switch connector from wiring harness connector.
2. Connect a suitable ohmmeter between terminal Nos. 1 and 2, Fig. 3. Continuity should be shown. Fully depress engagement switch button. Circuit should be open.
3. Connect ohmmeter between Nos. 1 and 3 terminals. No continuity should be present. Fully depress and then partially release engagement switch button. Continuity should be present.
4. Release engagement switch button and move control switch to RESUME position. Continuity should be present. Move control switch back to ON position.
5. Connect ohmmeter between Nos. 2 and 3 terminals. No continuity should be shown. Fully depress and then partially release engagement switch button. Continuity should be present.

Fig. 4 Wiring harness resistance chart, late model systems:

Fig. 5 Cruise control vacuum & wiring schematic:

1982---83 Buick Electra, LeSabre, Regal & Riviera
1. Disconnect engagement switch wiring harness from main wiring harness connector at points F and C. Disconnect connector from resume valve at points X and Y. Refer to Fig. 4. Connect ohmmeter between point C and ground. Ohmmeter should read between limits outlined in Fig. 5.
2. Disconnect wiring harness from transducer at points D and G. Connect ohmmeter at points C and X and measure resistance. Ohmmeter should read between limits outlined in Fig. 5. If resistance is not between these limits, check brake switch operation. If brake switch is good, replace wiring harness assembly.
3. Check continuity of ground wire from point Y to ground. Repair if necessary.
4. Measure resistance between point D to ground. Resistance should be 5---6 ohms.
5. Apply 12V to transducer hold terminal. Hold terminal should engage and release upon removal of 12V. Replace transducer if defective.
6. Reconnect connector at points X and Y on resume valve and point G on transducer. Apply battery voltage to point D. Resume valve should pull in. Replace valve if defective.




ELECTRIC BRAKE SWITCH TEST
1. Remove connector from brake switch and attach ohmmeter across brake switch terminal.
2. Depress brake pedal. Ohmmeter should show open circuit. Release brake pedal. Ohmmeter should show continuity. Replace brake switch if necessary.