4020 cranking

O.K. I feel foolish even asking but I'm stumped. I borrowed the in-laws 4020 a couple weeks ago( first mistake),pouched the starter (rebuilt it, second mistake). While not infallible I am a mechanic by trade so feel somewhat insecure at this point.
The tractor is still 24 volt. The problem is about the sixth or seventh time it is started when you shut off the tractor it starts to crank. You need to unhook the batteries for a while and it is o.k.
The starter seems o.k. the solenoid is new(twice)
the drive plunger moves freely. Is there some relay that could be energized with the key being shut off? I've seen gas engines continue to run
when a diode in the alternator is blown.

To crank you need to power up the starting solenoid. The wire to the solenoid comes from the ignition switch. If internally, there are metal shavings linking power and start, or decomposing and contaminated insulation, you can experience what you say. Apparently while running the link starts burning from the repeated starts and to stop it and allow it to cool down, you have to remove your power source.

What you may not know is that your starter was probably running, after the first few starts, while you were running the tractor.

I'd opt for a new ignition switch and hang onto your wallet.

Mark

If it is a 24v old style tractor, check the wire on the small post on the outside of the solenoid. If that wire becomes grounded, the tractor will try to start. Sometimes it becomes grounded between the starter and the push button.

I figured the starter was energized while the tractor was running also but that does not seem to be the case, I have power to the solenoid when this happens, the switch and start button seem to work fine and I"ve plugged in other switches and when I unhook the batteries and walk away for 15 minutes
I can hook up the batteries and all is good for a while. I will check the wire for a short to ground.

JD 24V electrical systems have no other factory installed solenoid control relay similar to later model 12V systems other than the solenoid on the starter. Mke you life better. Change tractor over to 12V. If mother-in-law & WIFE ain't happy NOBODY'S HAPPY :lol:

I've had a lot of tractors and I am a senior citizen....memory thing. I have had a 4020 with the 24 volt system and a 4010 with the 12v system, 4230 12v system, along with half dozen Fords, MF's, IH products, and who knows what all.

My comment was made from my memory of my 4020 24 volt system and I had that tractor like 20 years ago. I am remembering a very complicated switch, diameter of which was larger than a silver dollar, that had + and - 12v inputs (the way the 24v system was setup....+12v to -12v = 24v....that is why I associated it with my 4020. I do not remember if it started with a button or just turning the switch to start...just don't remember. I have some Fords that had both and remember the MF was key start. Don't remember on the IH. I was of the impression that it was the latter.....key start on the 4020.

You are not talking about rocket science. Heat is making a conducting path somewhere for voltage to get to your starter solenoid energizing coil in a sufficient amount that it can close the contacts and spin your starter. There is a path and heat has something to do with it.

Tell you what. Next time you start your tractor, remove the hot small wire from the starting solenoid after you get it started. If you need to restart it, touch the wire to the terminal, get it running and remove it. See if it self starts under that condition.

I'm not there so this is the best that I can do from here.

Mark