If the rectifier/regulator is getting hot the stator is working. What you need to check is if the charge is getting to the battery or is it all being shunted to ground because it has nowhere else to go, that will cause the reg/rec to get hot quickly. With a volt meter attached to the battery read the voltage with the key off then start the engine and see if the voltage goes up. If not there is a problem somewhere between the reg/rec and the battery. Most common is the connection on top of the starter solenoid.