Massey 44 negative ground conversion won't start

I have a Massey 44 work tractor. It was long ago converted to 12V with a positive ground alternator, and since the alternator bearing went out I decided to quickly convert the 44 to negative ground so a new alternator wouldn't be as pricey.

I traded the poles for the wires on the coil and the amp gauge and battery. Problem is, now the starter just clicks and gets hot. All the big battery cables get hot if the start button is held down for a second or two.

Yesterday the old positive ground alternator was threatening to disintegrate but the tractor started and ran fine. Today the new negative ground setup won't turn the starter.

What could be the problem?

I would assume battery cable not tight, polarity makes no difference.

Good chance the starter has now gone bad

well its hard to say what has been done to that tractor. they came with a push button starter. what ever you have done has nothing to do with the starter cranking the engine. . . so check the starter by removing it as it may be stuck. plus those push button switches give trouble. plus with cables heating means I would look mostly at the starter. it don't matter pos. or neg. ground the starter will still spin. also with 12 volt that is very hard on the Bendix and ring gear, and another reason to pull starter. there you go.

The starter would still turn the same direction regardless of polarity so I don't see any polarity swap as the problem. If the starter and cables get hot that tells me excess current is being drawn so here are a few thoughts. Since you changed battery polarity check those connections !!!!!!!!!!!!!!!!!!!!!!

1) Starter could be mechanically stuck/jammed into the flywheel. Using 12 volts on an old 6 volt starter can be tough on the drives, maybe it is damaged?? Try rocking the tractor in high gear to see if it releases. Try loosening the starter mount bolts to see if it frees up.

2) Just to be on the safe side I would remove, clean n wire brush, each and every battery and starter and ground cable connection. If any cables, grounds, or connections are hot or smoking that needs fixed ASAP

3) The starter switch (or if a solenoid) contacts can get burned pitted and corroded and get hot and resistive hampering the starter motor cranking.

4) The starter motor itself could be bad. Armature may be shorted or dragging,,,,,,,,Bushings can be worn,,,,,,,,,,,Fields may be shorted.

5) Battery may be bad. Is it full charged ???

There can be other causes, maybe the other fine gents can come up with more ideas. Insure drive gear isn't stuck/jammed,,,Insure all cables and connections and grounds and battery posts are good,,,,,,,,,,Insure good and full charged battery,,,,,,,,,,Check for excess voltage drop and heating across a bad starter switch...??.

John T

I'm thing it's just a coincidence that it's not cranking.

If all you did was reverse the polarity, the starter won't care.

John T covered all the bases.

It is easy to see that over the years that more cranking problems are caused by bad cable connections than all other causes. This includes positively, absolutely clean connections. It has happened to me.