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:

WIRE HARNESS TEST
Exc. 1982---83 Buick Electra, LeSabre, Regal & Riviera
1. Disconnect engagement switch wiring harness from main wiring harness connector.
2. Connect ohmmeter between point C and ground. Refer to Fig. 4. Ohmmeter should read between limits shown in Fig. 5. If resistance is above or below limits, disconnect connector from transducer and measure resistance of wire between points C and D. Resistance should be between limits shown in Fig. 5. If resistance is not between limits, replace main wiring harness.
3. Connect ohmmeter between point E and ground. Resistance should be between 5---6 ohms. Replace transducer assembly if limits are exceeded.
4. Connect ohmmeter between points F and G. Continuity should be present.



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.