Cranking issues

Went out to start a "fairly new to me" 860 ford. Normally I would turn to key to the on position, hit the thumb button, and it fires right up. Today I turned the key and the starter started cranking before I hit the button. Turned it off, and then back on, and then hit the button. It cranked but didn't start. Let go of the button and starter kept cranking. Turned the key off and it seemed like it was still wanting to crank, so I pulled the battery cable off. Checked terminals on ignition switch for continuity and have none in off position. Is my problem the 3 terminal solenoid? I pulled the starter cable off of it and hooked up the battery. I have 12 volts to the battery side of the solenoid and the small terminal, and nothing on the started terminal, until I turn key to on position. I hear a click and have 12 volts on the starter terminal until I turn the key off. My starter button looks and feels the same is there a way of testing it, to see if it's stuck.
Thanks for any help.

Go chance the solenoid is sticking whack it with the handle of a screw driver a couple times and see if that unsticks it. If not likely is has welded it self up real good which is common caused by a weak battery

On an 860 with a 3 terminal solenoid, your key should have
nothing to do with it cranking. The key switch is just two
wires, on and off to the coil. Nothing else.

I have had several 3 terminal solenoids stick shut and the
starter keeps cranking. But they do it key on or key off.

The starter on that tractor, as designed, will crank with the
key off if you push the starter button.
Not so on later models with the four wire solenoid.
Your readings all look right, up until you say you turn the key on
and the solenoid clicks. That isn't adding up for me.

There is a way to test the starter button. It is just an on/off
switch that provides ground to the solenoid.
Remove the small wire from the solenoid and measure resistance
from the wire to ground. It should be open/infinite. Then push
the button down. It should be a direct short - zero ohms.

I think I would look at the wiring real close and see if a wire
has came loose, turned, touching something else, etc.
Off the top of my head, I can't think of one that would cause
your symptoms though. I'd be real interested in what you find.

Are you sure its not an 861 with a four wire solenoid?
You did say it was fairly new to you, so it doesn't hurt to check.

I am sure this is an 860 with a 3 terminal solenoid. Serial number makes the tractor a 1955. Don't know who converted to 12 volts or if they knew what they were doing. The starter button will not crank unless the key is on. Never has since I got it. I'm sure of that.
I have the cable removed between the solenoid and the starter, so I can try and trouble shoot the problem. With key off I have 12 volts to battery side and small terminals of solenoid. When I turn the key on I can hear a 'click' from inside the solenoid and will have 12 volts to the starter terminal on solenoid. If I remove the wire going from the ignition switch to the starter button and turn the key on, I hear that click and have 12 volts to starter terminal. Turn the key off and I no longer have 12 volts at starter terminal. I don't think this is original ignition switch, as it has off, run, and start positions. It has one wire that goes to the small terminal on the solenoid, another that goes to the starter button, on that post is a wire that runs to the ammeter. Another post has a third that goes to what looks like a resister, that goes to the coil. There's nothing on the post for the start position. I'm not an electrician or a mechanic as you can tell. I don't think the solenoid is stuck because when I turn off the ignition I no longer have 12 volts on the starter side of the solenoid.
When I got the tractor it had to be jumped to start it. I noticed a wire going from battery terminal of solenoid to ammeter. I removed that wire and ran it to the ignition switch. Since then it's been a great starting tractor. I did just replace the wires going from the headlight switch to the front headlights. Thinking I might have messed things up, I disconnected those wires but it hasn't made a difference. Could I have shorted something with the headlights?

I think it's engaging with ignition switch on without pushing starter button. If I remover wire from Ignition switch to starter button, it still engages. I'm pulling my hair out and don't really have enough hair to do that ...

There should not be a wire from the ignition switch to the solenoid. Now if you pull the small wire off the solenoid and it still does that then the solenoid has welded up on you so do as I say and tap it a few times if that does not work replace it he solenoid that is

Ok, now I think I'm following. That's not the original wiring for sure.
The "starter button" I was talking about is on the transmission
cover, just in front of the shifter and applies ground to the
original solenoid to start it. Not power, ground.
Is that the same one you are using? It doesn't sound like it.
That switch is also the neutral safety switch to prevent the
tractor from being started while in gear.
If you remove the small wire from the solenoid, do you still
have 12V on the small terminal key off? I ask because if it is
the solenoid, you will need to know which type it is to replace it.
There are different 3 terminal solenoids, wired differently
internally, and of course, they won't interchange.

"That's not the original wiring for sure."

Bingo.

Yet another reason to avoid 12V conversions.

Not practical to diagnose in a chat forum.

Dean

Yes, my starter button is on the transmission cover by the shifter. It has one wire going to it, coming from the ignition switch. Old says it needs to be coming from the small terminal on the solenoid. If I remove the small wire from the small terminal on the solenoid I still have 12 volts to that terminal.
Thanks for your help with this by the way.

Well, at least you still have the NS switch in there.
That wire originally went straight from the switch to the
small terminal on the solenoid, just as Old said.
You could put it back that way.
With the small wire disconnected does the starter still spin?
If not, you have a wire grounded somewhere or the switch
could be bad. You can test it as I posted before, but try it
right at the switch terminal with the wire disconnected there.

This should help - I Googled "Ford 860 Tractor / Ignition Schematic" and this is what I got.

1957 Ford 860 Wiring Diagram


Doc :>)

(reply to post at 03:47:33 09/02/14)This should help - I Googled "Ford 860 Tractor / Ignition Schematic" and this is what I got.

1957 Ford 860 Wiring Diagram

Click to expand...

The title at the bottom of that drawing says "600/800 1 wire 12V conversion", and yes, that is one way to wire it when you convert it.

thumb starter button should never go to the key switch!

(quoted from post at 11:42:19 09/02/14) thumb starter button should never go to the key switch!

Click to expand...

No it shouldn't, but who knows what a previous owner might have done.

really shows you that some people have no concept of how things work...

Thanks, this will help ...

I'll check this tonight if I can. Thank you....

I knew the wiring was going to need work when I bought the tractor last month. I was hoping to fix the boiling gas issue I have with it and finish bush hogging before I tore into it. I'll make sure the battery's fully charged, and I'll run the wire from the small terminal to the starter button and see how that does.
Thank you.

whacking hasn't helped, I'm going to move some wires around and see if it makes a difference.
Thanks.

don't worry.. I wasn't referring to you.. I was talking about the prev owner that wired it wrong.

when we buy a tractor we are merely victoms of who owned it prior.