Inoperative Cruise Control

Check all items indicated under Erratic Cruise Control Performance. Unplug terminal connector at regulator, then reconnect so that white wire is plugged into hold terminal and brown-white wire is not connected to a terminal. Proceed with testing as follows:

1. Turn ignition switch to "ON" position, depress engage switch halfway and hold in that position. A "thunk" should be heard indicating the regulator is engaging. If no "thunk" is heard check fuse, and brake switch adjustment. Check that regulator circuit between hold terminal and ground reads 4-6 ohms. Check engagement switch. See ELECTRICAL SYSTEM . Check white wire at regulator for battery voltage. If all conditions check good and no "thunk" is heard, regulator requires replacement.
2. With vehicle in "PARK" position, start engine and depress engage switch halfway. If engine accelerates, proceed to step  5). If engine speed does not increase, disconnect orifice tube hose at regulator and plug hose. It engine speed now increases proceed to step  5). If engine speed still does not increase, a vacuum leak or restriction is indicated. Disconnect large hose connected to regulator and check for vacuum at regulator fitting.
   NOTE: Engage switch should still be depressed to halfway position.
3. If no vacuum is found at regulator fitting, remove engine manifold vacuum supply hose at regulator and check at hose for vacuum. If vacuum is present at hose, regulator requires replacement. If vacuum is not present at hose, check the vacuum supply hose and vacuum fitting at engine.
4. If vacuum is found at regulator fitting, reinstall large hose at regulator. Remove hose at servo unit and check hose for vacuum while engage switch is depressed halfway. If vacuum is present, servo unit requires replacement. If no vacuum is present, check hoses and fittings to regulator, then check brake release valve and hose.
5. If engine speed under step  2) showed an increase, check brown-white stripe wire using one of the following methods: Use an ohmmeter to check wire using procedure previously described under Electrical System in this article. An alternate method is to connect a voltmeter to the disconnected brown-white stripe wire and check for battery voltage with the ignition switch in the "ON" position. If check shows wire to be good, regulator requires replacement.