Glow Plug Test C - Test Lamp Does Not Light
- Ensure ignition has been off for at least one minute, then turn ignition on. If "GLOW PLUG" dash lamp comes on, perform GLOW PLUG TEST E. If not, for engine at normal operating temperature, condition is normal. For coolant temperatures below normal, turn ignition off, wait 2 minutes, and turn ignition back on. If light comes on, perform GLOW PLUG TEST E . If light does not come on, go to next step.
- Check batteries for sufficient charge. Batteries should be able to crank engine. If charge is okay, go to next step. If charge is low, charge or replace batteries. Repeat GLOW PLUG SYSTEM TROUBLE SHOOTING .
- Turn ignition off. Wait at least one minute, then connect 12-volt test lamp between power relay output and ground. See Fig 1 . Turn ignition on. If test lamp comes on but "GLOW PLUG" dash lamp does not, repeat GLOW PLUG SYSTEM TROUBLE SHOOTING . If test lamp does not light, go to next step.
- Check fusible link between ignition switch and control switch. If fusible link is okay, go to step 8. If fusible link is not okay, replace fusible link, and go to next step.
- Repeat GLOW PLUG SYSTEM TROUBLE SHOOTING . If fusible link blows, go to next step. If fusible link does not blow and system operates correctly, testing is complete. If fusible link does not blow and system still does not operate correctly, go to step 8.
- Remove signal (Purple) lead from power relay. Replace fusible link. Turn ignition on and then off. If fusible link blows, go to next step. If fusible link does not blow, replace power relay. Repeat GLOW PLUG SYSTEM TROUBLE SHOOTING .
- Disconnect chassis harness from engine harness. Replace fusible link. Turn ignition on and then off. If fusible link blows, repair chassis wiring harness and repeat GLOW PLUG SYSTEM TROUBLE SHOOTING . If fusible link does not blow, go to next step.
- Turn ignition off for at least one minute. Reconnect all leads, including power relay signal (Purple) lead. Turn ignition back on. Check voltage between power relay signal lead and ground. If voltage is at least 11 volts, go to next step. If less than 11 volts, go to step 10.
- With ignition off, check voltage between power relay input terminal and ground. If voltage is at least 11 volts, check power relay ground connection or replace relay. Repeat GLOW PLUG SYSTEM TROUBLE SHOOTING . If voltage is below 11 volts, charge or replace batteries and/or repair wiring from batteries to power relay. Repeat GLOW PLUG SYSTEM TROUBLE SHOOTING .
- With ignition off, disconnect power relay signal (Purple) lead. Disconnect engine harness at control switch. Check resistance between control switch connector Pin No. 6 and power relay signal (Purple) lead. See Fig 1 . If resistance is less than one ohm, go to step 12. If not, go to next step.
- With ignition off, disconnect chassis harness from engine harness. Disconnect power relay signal (Purple) lead. Check resistance between chassis side wiring connector terminal No. 6 and power signal lead. See Fig 1 . If resistance is less than one ohm, replace engine harness. Repeat GLOW PLUG SYSTEM TROUBLE SHOOTING . If not, repair or replace chassis wiring. Repeat GLOW PLUG SYSTEM TROUBLE SHOOTING.
- Remove engine harness connector to control switch. Turn ignition on. Check voltage between control switch connector Pin No. 3 and ground. See Fig 1 . If voltage is at least 11 volts, replace glow plug control switch and repeat GLOW PLUG SYSTEM TROUBLE SHOOTING . If less than 11 volts, go to next step.
- Turn ignition off. Disconnect chassis harness from engine harness, Turn ignition back on. Check voltage at Pin No. 3 on chassis side of connector. See Fig 1 . If voltage is at least 11 volts, replace engine harness. Repeat GLOW PLUG SYSTEM TROUBLE SHOOTING . If not, repair or replace chassis wiring. Repeat GLOW PLUG SYSTEM TROUBLE SHOOTING .