THEORY OF OPERATION - CONTINUED
ELECTRICAL SYSTEM - CONTINUED
General. Engine supplies, ECM, fuel injection pump, and pressure sensors.
ECM Power Supply.
Power supply to ECM and system is drawn from 24 volt battery. Power supply for ECM has battery dis-
connect switch, engine start switch, fuses, ground bolt, ECM connector, and machine interface connector
N OT E
The ground bolt is the only component that is mounted on the engine.
ECM schematic shows main components for a typical power supply circuit. Battery voltage is normally
connected to ECM. Engine start switch input turns on ECM.
Wiring harness can be bypassed for troubleshooting purposes.
Display screen on Electronic Technician (ET) can be used to check voltage supply.
ECM power supply comes from MIC, which receives power from power relay.