I've got a 3020D still running the 24V system. This spring I had the starter rebuilt (it was cranking slowly, and ended up needing a new armature--it was cooked); upon putting it back on I found that sometimes it would not engage... but after a few tries would. I lived with it for the summer, but, very occassionally it would stick "on", but disengaged and not cranking the motor. This past weeknd it got worse--yet I found if I knocked on the solenoid with a wrench, it'd stop spinning--but often it would continue to spin after I started the tractor so I'd have to listen for it and give it a few whacks.
I finally had time to take it down to the guy that rebuilt it, nice local guy that's familar with the 24V's and has rebuilt lots of these.
On the bench it was fine, but, he felt bad I had to pull it and puled the solenoid apart; put a new disc in the solenoid, and put a new pin/keeper in the fork (the other was a bit worn). I got home, put it on.. same exact issue; only now I can't seem to git it to disengage with a whack, I had to unhook the neg battery cable.
To be clear:
Battery connected, key on, button push; ~75% of the time, starter won't engage to crank engine. 100% of the time once I push the starter button, it seems to just runaway. ~50% of the time if it engages and cranks the engine, the starter continues spinning until I unhook the battery again. If I hook the battery back up, no problems, the starter stays off until I attempt another start of the engine.
I saw a recent thread on a 3010 12V that was staying constantly engaged with battery connected, this is not the same symptom as me-and it appears that poster found a wiring fault at the circuit breaker?
Ideas on this one? I've heard that with low cranking voltage the solenoid will arc and weld itself--but I don't know how that jives with it not engaging to crank the engine. Given how it's behaving, it's almost impossible to do a voltage drop test without burning up the starter because it somebody has to be ready to unhook it.
I did some more quick probing around.
1) if I take the starter button out of the picture and just jump the terminals with wire, same behavior.
2) I probed the yellow starter button wire and can't find that its inadvertently grounded--probed through the neut safety switch back to S terminal.
3) What voltages should i be seeing with everything off?
Between G lug on solenoid and the S lug on solenoid, I see 25+ V, with everything off. Same between G and the 2 lugs on back of starter joined by copper strap.
It's hard to check cranking because I have to reach down and unhook the negative from the battery to get the starter to stop spinning; but it's over 24V.