Isuzu NHR 4J Series, Workshop Manual

Page: 371 / 406

6D6 – 4 QOSII PREHEATING SYSTEM
QOSII SYSTEM TROUBLESHOOTING
Problems when the water temperature of the engine is 0°C below.
Condition Cause Circuit
Glow plug relay will
not be lit. Bad connection of FLW between battery and starter.
Bad connection or disconnection of starter SW circuit
Bad connection or disconnection Malfunction of other
of Fuse No . 8 circuits occurred
simultaneously.
Bad starter awitch.
Bad connection of glow plug relay terminal.
Disconnection of glow plug relay excitation coil.
Disconnection of circuit between glow plug relay and timer.
Bad glow relay. (The main contact does not pass electricity.)
Bad connection of timer.
Bad timer.
Bad earth circuit of timer.
Bad thermoswitch. (It remains ON even in water temperature below 0°C.)
Earth short-circuiting of thermo SW.
3
2
1
6
7
7
6D6-4-1.tif