Ford 3000 starter circuit trouble

Hello, everybody. I have a 1972 (I think) 3000 gas tractor. When I start it, the solenoid stays closed when I return the switch to the run position, causing the starter to continue running. I ruined one starter because of it, and have replaced the solenoid and the ignition switch. The problem remains. What am I missing?
 
It sounds like the ignition switch is not wired properly. In the start position, power goes to the starter solenoid. When returned to the run position, there should be no power to the starter solenoid. Look for the wiring diagram for that switch.
 
Don?t know if this is relevant, but don?t use cheap
solenoids. I had the original one do that, went
cheap and that one immediately started doing that,
got another (same make/model) as a warranty
replacement and that one did it, too. Lesson
learned, I bought a more expensive name brand
one and no more problems.
 
Every time you let go of your starter button/key, the current that was running through the solenoid interrupts through the process of an
electrical arc. This is like an arc welder in that material transfers from one contact to the other. After lots of those events, the remaining
material on the plates gets so small that the electrical current actually welds the contacts together causing your problem.

I have opened them up, turned the contacts around to clean sides, polished things off and put them back together for many more hundreds
of starts.
 


gas tractor, the "bypass lead" to the dist is on the wrong terminal and creating a backfeed to keep the selinoid on.
 
I'd think that'd be a problem from day 1 of the wiring error. What I said would come on by itself after years of satisfactory use.
 
If I have battery power to the switch, the on position sending power to only the coil, and the start position sending power to the starter solenoid, it should fix the problem and run, right?
 
Why would there be a second wire attached to the connector on the wire leading to the starter solenoid? Any idea where it might go?
If I am getting power to the switch from the battery, power to the coil in the on position, and power to the starter solenoid in the start
position, I should be good to go, right?
I think I am going to wire it with new wire, or at least give it a shot.
 
? Maybe to the Coil?
See SOTXBIL's reply.
That tractor used 2 circuits to power the coil.
1 - Thru the ignition switch and thru a resistor wire that limited the amperage thru the circuit when tractor was running.
2 - Off the solenoid with NO resistor wire to give a hotter spark/more amperage when the battery is pulled down during starting.

HTH
Keith
 

The reason for the second wire on the solenoid is to provide full voltage to the points while cranking. While cranking the amperage draw of the starter pulls battery voltage down. The wire from the ign sw to the points goes through a resistor. The voltage on that wire would drop down too low while cranking so they put a bypass wire triggered by the solenoid while cranking.
 
(quoted from post at 23:58:12 06/14/18)
The reason for the second wire on the solenoid is to provide full voltage to the points while cranking. While cranking the amperage draw of the starter pulls battery voltage down. The wire from the ign sw to the points goes through a resistor. The voltage on that wire would drop down too low while cranking so they put a bypass wire triggered by the solenoid while cranking.
ut that wire shouldn't share a solenoid terminal with anything else.
 

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