Ferguson TO20 12 volt conversion

Hello, Ferguson TO20 owners. I've installed the 12 volt conversion kit and the pertronix ignition kit from Yesterday's Tractor. The kit contained a new wiring harness and diagram so all the old wiring was pulled out and the new installed. My problem is that when wired as instructed, the tractor will not turn off when you turn off the ignition key. It starts and runs beautifully and really makes me smile until I tried to turn it off. I turned off the gas in order to stop it. I triple checked the wiring and it is exactly what the diagram indicates. Any ideas?? I did the same conversion to my Ford 9N last year and it is still working perfectly. Thanks in advance

(quoted from post at 18:10:48 09/05/23) Hello, Ferguson TO20 owners. I've installed the 12 volt conversion kit and the pertronix ignition kit from Yesterday's Tractor. The kit contained a new wiring harness and diagram so all the old wiring was pulled out and the new installed. My problem is that when wired as instructed, the tractor will not turn off when you turn off the ignition key. It starts and runs beautifully and really makes me smile until I tried to turn it off. I turned off the gas in order to stop it. I triple checked the wiring and it is exactly what the diagram indicates. Any ideas?? I did the same conversion to my Ford 9N last year and it is still working perfectly. Thanks in advance

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an't say anything much without the "as wired" diagram, except that it is not right. Better remove a battery cable before you have a dead battery.

Hello Woodog welcome to YT! Looking at the parts
picture for the YT 6 - 12 volt conversion for your TO 20
they are showing a Delco 10si alternator that has been
converted to a ..one wire.. alternator by utilizing a
special internal regulator. That means it only has one
wire connecting to the terminal stud on the back. Then
on the side near the rear edge there is a rubber plug in
the location two spade terminals would be for
connecting the two additional wires it would need in a
stock application. My best guess is that either YT
supplied you with a wiring diagram that is in
error(doubtful) OR you missed a minor detail while
transferring the diagram to reality on the tractor. I am
going to say you have connected the opposite end of
the wire going to the alternator at the wrong position. I
see those Fergies have an ammeter. One wire on that
that ammeter should be going direct battery power
either on the starter or starter switch. That should be
the only wire on that terminal of the ammeter. The wire
connecting to the alternator should go on the opposite
terminal of the ammeter. Any other wires connecting to
the ammeter except for the one that goes to the
battery should be on that terminal as well. You most
likely have the wire to the alternator on the ignition
switch terminal that feeds the coil, that is incorrect. If
the ammeter reads backwards as in a discharge
instead of a charge when the engine is running and the
alternator is charging you will need to swap the wires
on the ammeter side to side. Check it out!

It might help if you could post a picture of the wiring diagram and confirm that the alternator is a one wire one.

Thanks for the quick reply. To avoid draining battery, I have disconnected cable. When running, the alternator shows plus charging, so that part of the wiring is correct. I'm thinking about putting a toggle switch in the positive wire to the coil, that would be one way to stop the engine. HA! I've tried to send a picture of the wiring diagram, but my computer skills are not that highly developed. Thanks for all the comments. It runs and charges; and I'm pretty happy it starts so quickly with the electronic ingnition.

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(quoted from post at 04:24:38 09/09/23)

Thanks for the quick reply. To avoid draining battery, I have disconnected cable. When running, the alternator shows plus charging, so that part of the wiring is correct. I'm thinking about putting a toggle switch in the positive wire to the coil, that would be one way to stop the engine. HA! I've tried to send a picture of the wiring diagram, but my computer skills are not that highly developed. Thanks for all the comments. It runs and charges; and I'm pretty happy it starts so quickly with the electronic ingnition.

Click to expand...

It will show charge even if you have the alternator wire connected to the ignition side of the switch. Yes, it works but not correctly. The way you have it you are likely running the high charging amps through the ignition switch. That may eventually cause your contacts in the switch to fail. Test your alternator terminal to see if it has voltage with the key off with the engine stopped, it should. If there is no voltage that will also confirm it is wired incorrectly. Wired correctly the alternator terminal will always have voltage. Also it would be helpful if you would confirm if it is a ..one wire.. alternator. If so you most certainly have it wired incorrectly. If the alternator is a 3 wire, it would still be incorrectly wired but the cause would involve the connection of the wire connected two side plug terminals labeled ..1.. on the alternator.