No Start (Cold)
Perform these diagnostic procedures if engine does not start when cold; GLOW PLUG light may or may not come on. Before proceeding, check fuel system to ensure it is okay. Ensure battery voltage is 12.4 volts or more with ignition turned off. Ensure cranking speed is at least 100 RPM.
- Turn ignition off. Check voltage at battery stud (single lead) on glow plug. See Fig 1. If voltage is present, go to next step. If voltage is not present, repair battery-to-glow plug controller circuit.
- If voltage was present in step 1), turn ignition off and check voltage at glow plug feed stud (twin lead) on glow plug controller. If battery voltage is present, go to next step. If battery voltage is not present, relay contacts are shorted. Replace controller and all glow plugs.
- If voltage is present in step 2), disconnect harness from all glow plugs. Check resistance between glow plug terminals and engine block. Replace glow plug if resistance is greater than 2 ohms. Reconnect all glow plugs before continuing with diagnosis.
- With all glow plugs reconnected, place ignition switch in RUN position. Remove controller connector and check voltage at harness connector terminal "D". See Fig 1.
- If no voltage is present, repair open in ignition feed circuit to controller. If voltage is present, check resistance between terminal "E" of connector and engine block (ground). If resistance is greater than one ohm, repair ground circuit to controller.
- With ground circuit working properly in step 4), check resistance between terminals "C" and "E" of connector. If reading is greater than 2 ohms, go to next step. If reading is less than 2 ohms, go to step 8).
- If reading in step 6) was greater than 2 ohms, check for excessive resistance in voltage sense circuit to controller. Repair as necessary.
- If reading in step 6) was less than 2 ohms, reconnect controller harness connector and ensure complete engagement. Connector locking latch should click over controller locking tab. With controller connector harness correctly connected, check voltage at glow plug feed stud (twin lead) on glow plug controller, while turning ignition switch from OFF position to RUN position.
- If voltage is not present, replace glow plug controller. If battery voltage is present, check voltage at any one glow plug harness connector when turning ignition switch from OFF to RUN position. Test both right and left banks.
- If no voltage was present in step 9), repair glow plug feed circuit to glow plugs. If battery voltage is present and instrument panel GLOW PLUG light does not come on, locate and repair bulb or circuit.