Inspection, Replacement and Adjustment of the Starter Interlock Switch

INSPECTION
PROCEDURE

1. The starter interlock switch is located near the upper end of the clutch pedal. Two wires are connected to the switch: one from the starter relay and one ground. When the ignition key is turned to START and the clutch pedal is depressed, the switch closes to ground, which energizes the starter relay and activates the starter motor.

2. If the engine does not crank with the clutch pedal depressed, adjust the switch and try again. If adjustment does not solve the problem, check the switch and replace it if necessary. If the engine starts with the clutch pedal released, adjust the switch and try again.
3. If the engine does not crank when the clutch pedal is depressed, either the continuity between the switch terminals is interrupted, or no voltage is supplied to the switch from the starter relay.
4. Check the voltage supply with a voltmeter or test lamp. When the ignition key is turned to START and the pedal is depressed, voltage must be present on the wire from the starter relay. If there is no voltage, check the wiring between the relay and the switch for an open circuit. If voltage is supplied correctly, check for voltage on the opposite side of the switch (with the clutch pedal depressed). Voltage on both sides of the switch confirms that it functions correctly. Try adjusting it. If there is no voltage, replace the switch.

REPLACEMENT
PROCEDURE

Disconnect the wiring connector, loosen the adjusting nut, and unscrew the switch from its mounting bracket. Installation is the reverse of removal.

ADJUSTMENT
PROCEDURE

Loosen the lock nut and turn the switch until continuity exists between its terminals with the clutch pedal depressed.