New Holland WorkMaster 50 Service Manual page 662

Wiring harnesses - Troubleshooting Safety start circuit - Operator
present
Problem
Starter motor will not
energize
Starter motor energizes,
but fails to start engine
(lacks exhaust smoke)
Wiring harnesses - Troubleshooting Safety start circuit - Operator
not present
Problem
Starter motor will not
energize
Starter motor energizes,
but fails to start engine
(lacks exhaust smoke)
Electrical systems - Harnesses and connectors
Possible Cause
Insufficient battery charge.
Blown fusible link.
Defective key switch.
Defective PTO safety or safety start relay. Test relays and replace as necessary.
Malfunctioning safety start switch.
Malfunctioning starter motor.
Blown fuse ignition, 15 A fuse.
Defective operator safety module.
Defective fuel shutoff relay.
Malfunctioning fuel shutoff solenoid.
Possible Cause
Insufficient battery charge.
Blown fusible link.
Defective key switch.
Defective PTO safety or safety start relay. Test relays and replace as necessary.
Malfunctioning safety start switch.
Defective start circuit diode.
Malfunctioning starter motor.
Blown fuse ignition, 15 A fuse.
Defective operator safety module.
Defective fuel shutoff relay.
Malfunctioning fuel shutoff solenoid.
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55.4 [55.100] / 97
Correction
Test battery. Charge, add water, or replace
as necessary.
Inspect and replace fusible link as neces-
sary.
Test key switch and replace as necessary.
Test neutral range, main PTO transmission
clutch, and seat safety start switches for
adjustment, proper operation, and faulty
ground circuits.
Test starter motor and repair or replace as
necessary.
Replace fuse.
Test module and replace as necessary.
Test fuel shutoff relay and replace as nec-
essary.
Test fuel shutoff solenoid and replace as
necessary.
Correction
Test battery. Charge, add water, or replace
as necessary.
Inspect and replace fusible link as neces-
sary.
Test key switch and replace as necessary.
Test neutral range, main PTO transmission
clutch, and seat safety start switches for
adjustment, proper operation, and faulty
ground circuits.
Test start circuit diode and replace as nec-
essary. Operator must be out of seat for
test.
Test starter motor and repair or replace as
necessary.
Replace fuse.
Test module and replace as necessary.
Test fuel shutoff relay and replace as nec-
essary.
Test fuel shutoff solenoid and replace as
necessary.