Glow Plug Afterstart Diagnosis

Glow Plug Circuit:

To check proper operation of this circuit proceed as follows:

1. With the engine cold 27°C (80°F), turn the engine control switch to the RUN position and let the glow plugs cycle.
2. After 2 minutes crank the engine for 1 second. (it is not important that the engine starts.) Return the engine control switch to RUN. Glow plugs should cycle at least once after cranking.
3. If the plugs do not turn on, disconnect the controller connector, and check the connector harness terminal B with a grounded 12 volt test lamp. The lamp should be off with the engine control switch in RUN, and on when the engine is cranked.
4. If the lamp does not operate as just described, repair a short or open in the engine harness purple wire.
5. If the lamp works right, but the afterstart glow plug feature does not, replace the controller.