Matthew,
Possibly a safety switch or PTO switch section in the diagram shown here:
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Please note that for the 420, the parking brake switch is only on tractors with SN 595881 and above. Also, if you have only the front PTO switch there should be a jumper in the X5 connector as seen here.
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Does your tractor have the "starter improvement kit" fitted? If so that relay may have failed.
Absent the starter improvement kit, the conventional troubleshooting for the starter is as follows: Get a voltmeter and start tracing at terminal S2 of the key switch in the top diagram and go counter clockwise until you get voltage when you are in the RUN position.
If you have voltage at S2 in RUN, do you have voltage at the solenoid terminal S when the key is in the START position? If yes, then you have a bad solenoid. If no, then the key switch or its connector will be the issue.
Let us know if you have the relay kit, and we can give additional steps...
Chuck
Possibly a safety switch or PTO switch section in the diagram shown here:
Please note that for the 420, the parking brake switch is only on tractors with SN 595881 and above. Also, if you have only the front PTO switch there should be a jumper in the X5 connector as seen here.
Does your tractor have the "starter improvement kit" fitted? If so that relay may have failed.
Absent the starter improvement kit, the conventional troubleshooting for the starter is as follows: Get a voltmeter and start tracing at terminal S2 of the key switch in the top diagram and go counter clockwise until you get voltage when you are in the RUN position.
If you have voltage at S2 in RUN, do you have voltage at the solenoid terminal S when the key is in the START position? If yes, then you have a bad solenoid. If no, then the key switch or its connector will be the issue.
Let us know if you have the relay kit, and we can give additional steps...
Chuck
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