Preglow System Test (DE-04.09)

Preglow System Test (DE-04.09)

This test is divided into the following sections
A. Engine 602.96
B. Engine 603.96


A. Engine 602.96

Equipment
Multimeter
Fluke Model 23 with 80-410 current probe; SUN DMM-5

Wiring Diagram, Preglow System:

Note:
If preglow Indicator lamp lights for approx. 1 minute with engine running, or lamp does not light during preglow time, one or more glow plugs may be defective.

If lamp lights up continuously, the preglow time relay is defective and should be replaced.





Test

a. Preglow indicator lamp does not light up, but engine starts normally.




b. Preglow indicator lamp does not light up, engine cannot be started.























c. Preglow Indicator lamp lights up, engine is difficult to start





B.Engine 603.96

Equipment
Multimeter
Fluke Model 23 with 80-410 current probe; SUN DMM-5

Wiring Diagram, Preglow System:

Test

Preglow indicator lamp does not light up, but engine starts normally.







Preglow indicator lamp does not light up, engine cannot be started.

Model 124:

Model 126:

Preglow indicator lamp lights up. engine is difficult to start.













Note:
It is possible, due to unfavorable tolerances, that the indicator lamp will indicate a faulty glow plug only after 2 glow plugs in cylinders 2 to 4 (engine 601) or cylinders 2 to 5 (engine 602) have failed.

To make sure that the failure indication circuit is not defective, disconnect 2 glow plug leads of cylinders 2 to 5 and repeat preglow procedure.

If the preglow indicator lamp indicates a fault (does not light up), the preglow time relay is in order.