Indicator Does Not Glow, Engine Won't Start

Testing Main Circuit of Preglow System For Open Circuit

If the following complaint is received:
Preglow indicator lamp does not light up, engine does not start.





- Use the multimeter set to the Volts range to test the voltage at terminal 30 of the preglow time relay to ground.

- If no voltage is indicated, test red cable from starter, terminal 30, to the preglow time relay, terminal 30, for open circuit. Rectify open circuit.

- If voltage is indicated (approx. 12 Volts), test 80 ampere fuse for tight fit or open circuit; replace if necessary.





- If no fault has been found to this point, test voltage at contact 1 of the 4-pin connector of the preglow time relay to ground.

- If voltage is indicated when preglow system is switched on, test pink/red cable from fuse 7 (unprotected side) through plug connection of engine wiring harness to contact 1 of the connector of the preglow time relay for open circuit. Rectify open circuit.





- If voltage is indicated, connect contact 1 (terminal 15) and contact 4 (terminal 31) and test voltage. If no voltage is indicated, test brown cable from contact 4 to ground for open circuit. Rectify open circuit. If no fault has been detected so far, the preglow time relay is defective. Replace preglow time relay.