JD 1520 gas tractor

[petefarms]

JD 1520gas tractor replaced alternator and starter, battery cables 1 battery is last winter the other from previous winter. When I put battery cable on second battery, it immediately started heating up and positive terminal started smoking, and even the negative terminal was getting hot. Is this second battery I purchased last winter gone bad or was when purchased or is something else going on. First time I've seen this happen. Any ideas are appreciated. thanks.

[Roadking]

Certain pos to pos, neg to neg? I know, first thing checked.
Bad ground, continual draw, shorted cable somewhere would be my first checks.

Matt

[nosqrls]

sounds like leads are backwards dead short.

[Allen W]

12 or 24 volt set up?

[petefarms]

Cables are ok, its a 12v tractor.

[Robotron]

Negative or positive ground? Hook it up backwards and you have a dead short. You could have a bad diode in the alternator even though it's new.

[Roadking]

That could very well be the situation...

Matt

[Ray]

A starter can also have a dead short inside, from several reasons??? Most of the time it's not a dead short but battery draining over a few days from connection thru brushes, wire varnish wear, etc., If others ruled out disconnect starter wire from starter and see what happens? Probably not in starter but I have seen it happen several times over the years in heavy equipment, and cars.
I must admit it sounds like a dead short from reversing a wire???? Like mentioned earlier, some have neg. ground, some positive ground in DC electric farm engines. Should be easy to rule that out with an internet search on wireing diagram for the model, but someone could have changed it?? Some times i'ves even a voltage regulator reverse??? Can be switched back by draining and touching with pos. lead of battery, you can find procedure online easily. Hope you have it solved already, Best wishes, ray