[rotorwrench]

Polarization of the generator field pole shoes is necessary to get the gen to start generating after engine starts. A DC voltage applied to the field coils is what gives the residual magnetism to the shoes in there. This is why you disconnect the field wire from the regulator before momentarily touching it to the Bat terminal. This makes sure the north and south magnetic poles are aligned with the negative power side of the battery on a positive ground system.

The same principal is used to magnetize parts for Magnaflux inspections utilizing a DC voltage through a large coil of wire. Then to demagnetize, an AC coil is used to take the magnetic gause back out of the part.

If the generator is still getting hot after proper polarization then it's time to either replace the voltage regulator or have it tested by qualified electrical repairman. If it checks OK then it's time to look for a big short somewhere that isn't showing up through blown fuses or the like. A generator will get hot if it is charging at a higher than normal rate. A person has to find out why it's doing that. The battery should be tested by high rate discharge if possible. This will tell a person if it has enough capacity or if it is shorting out internally.