1650 electrical again

I posted earlier about issues with the staring system on a 1650. Did what rvirgilKS said, rechecked wiring and found a couple of crossed wires. Got it to start but sometimes the switch doesn't do anything then other times it will hit. Usually when it turns over it does so really slow, like it's not getting full voltage.
Got it to start once and found out the starter failed to disengage. Smacked the end and it dropped out. Is it possible that accidently leaving the key on fried the points and condenser and that is what is causing the problem. My multimeter died a bit ago and I haven't bought a new one yet so I'm going by a test light. Does the ignition wire have current running through it whenever the key is on or only when you are actually starting it?

Glad that you are making some progress.

"sometimes the switch doesn't do anything then other times it will hit" Do you mean the switch will not activate the solenoid, the solenoid will not activate the starter, or the switch will not supply power to ignition coil?

"Usually when it turns over it does so really slow, like it's not getting full voltage." Be sure battery is well charged. I would remove and clean both ends of both battery cables. Be sure clamps are in good condition and be sure connection where ground cable attaches to the frame is clean and tight. Battery cables have been know to have internal corrosion that can not be seen.

If there is a problem with the solenoid activating, there is the neutral safety start switch in the pink wire to the solenoid. It prevents starter activation when tractor is in gear.

"starter failed to disengage" Could be bad starter, or related to slow cranking speed, or low voltage.

"Is it possible that accidently leaving the key on fried the points and condenser and that is what is causing the problem." If left on for awhile could damage points and possibly coil. This would affect spark and ignition but not the starter.

"Does the ignition wire have current running through it whenever the key is on or only when you are actually starting it?" The wire from ignition on the switch, through the coil to the side of the distributor and through the points to ground will flow current when switch is on and points are closed, but no current when points are open. With test light on side post of distributor, light should glow when points are open but be off when points are closed.

Wire from I terminal on solenoid to coil will flow current only when starter is activated and points are closed.

Thanks, that give me some ideas. I had power to the ignition post on the switch as soon as the key was turned on. Any ideas? I'm getting a new multimeter this week so I can do some resistance and voltage testing on the wiring. Test light on cables to battery posts didn't appear to be bad cables, but you never know.

Have you had the starter checked to make sure it's working correctly? I had a starter on my pickup that kept needing more and more juice to get it to start cranking. Finally quit altogether and not even jump start booster would make it spin. Got the starter rebuilt and it works great now.

Do you have a wiring diagram or schematic for the tractor to use for diagnosing?

I'd have to look at my 1650 wiring diagram but there should be an ignition (switched power) terminal and a start terminal on the switch I would think. Ignition power terminal would get current when you turn switch on and start terminal would only get power when key switch is turned to start engine. That is when the solenoid should be getting power to engage the starter. Once engine is started the key switch should return to ON position and supply power to ignition power terminal.

You might just take out the starter and test it to begin with. It may need a new solenoid, could be shorting out. Then go from there. If you have the time those Delco starters are rebuildable for a just a few bucks.