very hot -battery cable

[PHIL850]

Clean the ends of both battery cables and where they connect on both the battery , block, solenoid/starter. Startup the tractor and measure charging voltage at the battery. charging voltage shouldn’t be more than 14.5 volts

 

[ruffdog]

I have an alternative thought on this. Getting the tractor wet is suspicious in the problem, but also the new alternator is suspicious because of the quick onset of the problem.

Alternators make AC and that goes directly into a rectifier to make DC before it is fed to the tractor / battery. The rectifier most of the time is right on the alternator. If one or more of these diodes in the rectifier are (bad / leaking / shorted / open) then weird things can happen like draining the battery and heating up wires.

I'd want to hook up an oscilloscope to the output of the alternator and see if there is pure DC or if there are some AC spikes/ ripples. Unfortunately a simple multi-meter will not pick up things like a rogue AC ripple in DC.

Yeah, I would have to agree. If the diode(s) in the rectifier are bad some real strange things can happen. It can cause many things to burn out all at one time, like light bulbs and igniters.

 

[Lawnranger]

It seems like once you confirm the battery is good, 90% of electrical issues are at the connections, then 10% beyond at the alternator or else. Good luck and keep us posted.