Farmall 400 battery goes dead

Farmall 400 12v positive ground. Battery goes dead overnight. when connecting positive ground after negative excessive sparks. To me indicates a draw somewhere. Noted with battery charger and battery connected to tractor can feel vibration in the fan blades and generator pulley. Normal? Or is the generator creating a draw possibly. didn't have my meter with me so just looking for suggestions till I can get a meter on it and start disconnecting things till draw goes away

I just had this problem on a super m. my
voltage regulator was shorted out inside.

If you changed battery polarity, BEFORE starting you should have Polarized the Generator, did you ??? If not you may have damaged the VR !!!!!!!!!!!! Was it NEG ground before ?????

If when you shut the tractor off it shows heavy battery discharge the VR's Cutout Relay may be stuck closed ??? If that's the case if the belt were removed the genny would spin...?.. If the cutout relay is stuck closed and the genny belt is in place the genny would try to run and overheat...??.DISCONENCT THE BATTERY FOR NOW

If you changed polarity the ammeter would read bass ackwards unless its leads were reversed. Similar if you changed polarity the coil lead should be reversed...???.

BEFORE re starting try to Polarize the genny just to see what happens and hope the VR isn't damaged and/or its cutout relay is stuck closed which will discharge the battery quickly and the genny may get hot as it tries to run

IN THE MEANTIME DISCONNECT THE BATTERY. Maybe use a charger to charge it,,,,,,,,,,,Re connect battery at the correct polarity and Polarize the genny,,,,,,,,,,,,,hope VR isn't fried or its cutout relay stuck closed

John T

Positive ground before. I recall the genny being warm so my guess would be relay stuck closed?? Refresh my memory as to how to polarize the genny... armature wire to positive?

As others are saying you most likely
toasted a set of points in the regulator.
Take the cover off and give them a look.
They should be free to move. Not welded
shut.

Thanks all
Will update asap

Your post has a confusing Statement "when connecting positive ground after negative excessive sparks" The tractor came from the factory with 6v
positive if gasoline, 12v if diesel. If you connected the battery backwards (negative ground) and sparks were made at the terminal, you probably
welded the points in the cutout relay in the regulator together. This causes the generator to be connected to the battery when stopped. If you put a
charger on the battery (now connected correctly) and the fan vibrated, that is what happened with a 90% probability. As John T indicates, disconnect
the battery, and charge it while not connected.
Tomorrow, or whenever, Disconnect the bat wire and arm/gen wires from the regulator. With an ohm meter, or a continuity tester, test between those
two terminals on the regulator. if they are connected, the regulator should be considered fried.
If they are open, no conduction, then (with the regulator disconnected) attach the charged battery. The Bat lead to the regulator will now be at
battery volts. Touch it to the Bat terminal on the regulator. If no sparks, good. if sparks, the regulator is toast again. If no sparks, touch the
Arm lead going to the generator to the Gen/Arm terminal on the regulator. If sparks, regulator is toast again. Replace it.
Do as John T indicates to polarize the generator when a new regulator is attached. Jim

Unless this is a show tractor, or you just have a need to keep the generator, this might be a good time to simplify your life and convert it to an alternator.

If it turns out to be a bad regulator, the new regulators are not the same quality as the original.

And a possibility the generator may have overheated if it sat with the cutout stuck long enough to discharge the battery.

Polarize BEFORE starting by momentarily jumping from BAT over to GEN/ARM terminal on VR.

Indeed a stuck closed cutout relay inside the VR can drain the battery and overheat the genny. If it stops drawing current if you remove the BAT or GEN/ARM wire it must be stuck closed

John T

Thanks Jan...son and JT