JD650 won't crank, please help!

oldneverslow · Mar 2, 2020

I purchsed a 1985 model. test drove and it was restarted several times. Hauled it home on a trailer and much jiggling neutral switches and it finally cranked and started. unloaded and parked in the shop. Ready to move it and it made 1 short starter engagement, then no voltage to starter wire. Traced wiring from ign switch to front PTO switch but open from there to transmission neutral switch. Can I just run a new wire to continue to starter from PTO switch to neutral switch? ALL neutral switches check perfect. Use jumper from battery to starter and starter engages correctly. I have the shop manual and wiring diagram but it is cut off on the wiring down to the seat switch and back. Switch tests correctly. Any suggestions? If someone has the full wiring diagram, could I please get a copy. I have read all the JD650 posts before purchase and again fighting this issue.

beenthere · Mar 2, 2020

:welcome: to TBN

I have the JD 670 tech manual, but not the 650.

Has the battery been load tested? All ground and battery cables removed and cleaned? Just to rule out corrosion at the connections.

Roadworthy · Mar 3, 2020

If you have a defective wire you can certainly replace it. Check to make sure the connectors have not separated from the wire internally. You may just need to cut the connectors off and replace them. It's also possible the wire is chewed or broken somewhere between point A and point B.

BertZegers · Mar 3, 2020

It is best to test the suspect switch or switches with a voltmeter parallel over the switch . Than start. If the voltmeter reads a voltage than the switch is bad. If you do it this way, you test the switch with 12 volt and with the real load current. Test parallel over the circuit or over a wire to find a bad wire and bad contacts.
A multi meter on Ohm will test with 1.5 volt and near zero current. Multi meters on OHM show "open" or "closed", not good or bad.

oldneverslow · Mar 3, 2020

Thank you for all the responses. I have used a 12v source through the switches and tested all successfully. I'll ask for the wiring diagram to be certain I'm on track to jumper the open wiring. I have visited here for about 8 years and enjoyed my education as well as the occasional humor. Thanks again!

oldneverslow · Mar 5, 2020

SOLVED! I bypassed the open wire and had continuity from the ignition switch through the neutral switches all the way to the starter. Then connected the battery and discovered the ignition switch was operating intermittently. It does not connect the battery to the starter circuit. I disconnected the wire from the post and no voltage when switched to crank position. All other circuits work through the switch. New switch on order so now time to sharpen the MMM blades and do spring maintenance.