Glow Plug Test E - Test Lamp Does Not Cycle

NOTE: There has been a factory update to Glow Plug Testing, See TSB Number 88-11-19 in the TECHNICAL SERVICE BULLETIN Section

Connect a test lamp between glow plug power relay output and ground. Turn ignition on, but do not start engine. If test lamp lights, proceed to step 2. If test lamp does not light, for coolant temperatures of 140° F (60° C) or above, condition is normal. For coolant temperatures below 140° F (60°C), turn ignition off, wait 5 minutes, and turn ignition back on. If lamp lights, proceed to step 2. If lamp does not light, perform Glow Plug Test C.
Turn ignition off. Disconnect engine harness from control switch and all glow plugs. Check resistance between control switch connector pin 4 and power relay output connector. If resistance is less than 1 ohm, proceed to step 4. If resistance is 1 ohm or more, proceed to step 3.
Turn ignition off. Disconnect chassis harness from engine harness. Disconnect fusible links from chassis harness. Check resistance of the fusible links. If resistance is less than 1 ohm, replace engine harness and repeat trouble shooting procedure. If resistance is 1 ohm or more, replace fusible link(s) and repeat trouble shooting procedure.
Turn ignition off. Check resistance between control switch connector pin 5 and ground. If resistance is less than 1 ohm, proceed to step 5. If resistance is 1 ohm or more, repair or replace harness ground connections as necessary and repeat trouble shooting procedure.
Turn ignition off. Disconnect wiring harness from latching relay. Check resistance across latching relay terminals 1 and 2 using positive probe on terminal 2 and negative probe on terminal 1. Resistance should be 45 ohms or greater. Reverse ohmmeter leads. Resistance should be greater than 1 megohm. If resistance is not as specified, replace latching relay and repeat trouble shooting procedure. If resistance is ok, proceed to step 6.
Turn ignition off. Disconnect wiring harness at control switch. Connect all other leads. Check resistance between control switch connector pin 6 and ground. If resistance is less than 2.5 ohms, replace power relay and repeat trouble shooting procedure. If resistance is 2.5 ohms or more, proceed to step 7.
Disconnect wiring harness from control switch. Turn ignition on, but do not start engine. Check for voltage between switch harness connector pin 1 and ground. If voltage is detected, turn ignition off and proceed to step 8. If no voltage is not detected, turn ignition off, replace control switch, and repeat trouble shooting procedure.
Leave harness disconnected at control switch. Disconnect engine harness from chassis harness. Turn ignition on. Check for voltage at chassis harness connector pin 1 or 5. If voltage is detected, proceed to step 9. If no voltage is detected, replace engine harness and repeat trouble shooting procedure.
Disconnect engine harness at control switch and chassis connector. Turn ignition on. Remove connector from after-glow relay. Check for voltage at chassis connector pin 1 or 5. If no voltage is detected, turn ignition off, replace after-glow relay and proceed to step 10. If voltage is detected, turn ignition off, repair or replace chassis wiring from relay to engine harness connector and repeat trouble shooting procedure.
Disconnect engine harness at control switch and chassis connector. Reconnect after-glow relay. Turn ignition on. Check for voltage at chassis side of chassis connector pins 1 and 5. If voltage is detected, repair or replace wiring and/or alternator as necessary, then repeat trouble shooting procedure. If no voltage is detected, problem is solved. Repeat trouble shooting procedure.