Test D
- Turn ignition and cruise control on. Disconnect cruise control vacuum pump connector. Using voltmeter, measure voltage at vacuum pump harness connector terminal No. 82a (White/Blue wire) and ground. Battery voltage should exist. If voltage is as specified, go to next step. If voltage is not as specified, repair short to voltage in White/Yellow wire.
- Turn ignition off. Disconnect cruise control vacuum pump connector. Connect a fused jumper wire between battery and vacuum pump White/Blue wire terminal. Connect a second jumper wire between ground and vacuum pump Black/Red wire terminal. If vacuum pump operates, go to next step. If vacuum pump does not operate, repair Black/Red wire or replace vacuum pump.
- With ignition and engine off, disconnect cruise control vacuum pump connector. Connect a fused jumper wire between battery and vacuum pump White/Blue wire terminal. Connect a second jumper wire between ground and vacuum pump Black/Red wire and Black/Yellow wire terminals. If cruise control actuator retracts, repair Black/Yellow wire. If actuator does not retract, check for vacuum leak or restriction, or replace brake switch vent valve or cruise control vacuum pump.