New Holland WorkMaster 50 Service Manual page 663

Wiring harnesses - Troubleshooting Safe Operation - Operator
Present
Problem
Engine does not continue
to run while operator is
seated
Engine continues to run
after operator has left
seat for more than two
seconds and mid PTO and
park brake is not engaged
Wiring harnesses - Troubleshooting Safe operation - Operator not
present, PTO "OFF"
Problem
Engine does not continue
to run while operator is
seated
Engine continues to
run after operator
has left seat for more
than two seconds with
transmission range in
gear
Wiring harnesses - Troubleshooting Safe operation - Operator not
present; PTO "ON"
Problem
Engine does not continue
to run while operator is
not seated
Electrical systems - Harnesses and connectors
Possible Cause
Defective seat safety switch.
Defective Fuel shutoff relay.
Malfunctioning fuel shutoff solenoid.
Defective operator safety module.
Open wiring in safe operation circuit.
Defective seat safety switch.
Defective operator safety module.
Malfunctioning fuel shutoff solenoid.
Short-circuit in wiring or faulty ground cir-
cuit.
Possible Cause
Defective neutral safety switch.
Blown 3 A diode.
Defective Fuel shutoff relay.
Malfunctioning fuel shutoff solenoid.
Defective operator safety module.
Open wiring in safe operation circuit.
Defective neutral safety switch.
Defective operator safety module.
Malfunctioning fuel shutoff solenoid.
Short-circuit in wiring or faulty ground cir-
cuit.
Possible Cause
Defective fuel shutoff relay.
47866583_ 02/12/2015
55.4 [55.100] / 98
Correction
Test seat safety switch and replace as nec-
essary.
Test relay and replace as necessary.
Test fuel shutoff solenoid and replace as
necessary.
Test module and replace as necessary.
Check for loose connectors, grounds, and
wiring damage.
Test seat safety switch and replace as nec-
essary.
Test operator safety module and replace as
necessary.
Test fuel shutoff solenoid and replace as
necessary.
Check for loose safety switch connectors,
grounds, and wiring harness for damage.
Correction
Test neutral safety switch and replace as
necessary.
Check diode, replace if necessary.
Test relay and replace as necessary
Test fuel shutoff solenoid and replace as
necessary.
Test module and replace as necessary.
Check for loose connectors, grounds, and
wiring damage.
Test neutral safety switch and replace as
necessary.
Test operator safety module and replace as
necessary.
Test fuel shutoff solenoid and replace as
necessary.
Check for loose safety switch connectors,
grounds, and wiring harness for damage.
Correction
Test relay and replace as necessary.