[Masteryota]

A burnt spot in a regulator is dead giveaway of a shorted leg in the regulator, and should remedy your charging issue, but be careful when you start it up, normally legs don't just short out, there may be another issue causing it. Be sure to clean all connections, including all of the ground wires.

In short, regulator/rectifiers take in alternating current from 2, 3, or 4 wire stators, and 'straighten' out the voltage, converting it from AC to direct current(DC). There are normally 3 diode 'legs'(also known as a diode trio) in the circuit, and each wire feeds into the circuit at a different point, and one leads out to the battery or power block, and another to ground, resulting in safe, 12v DC. Any excess voltage produced will be grounded, and converted to heat, which radiates from its heat sink(fins). Normally, the bigger, or more fins, it is designed for more voltage than normal use. An example would be a higher revving engine, which would produce higher AC voltages from the stator. This is also why you see voltage increase when the engine RPM increases, as the stator is producing more.

I say that, to say this. If you have the wire diagram for the engine, you can normally test each leg of the regulator circuit with a DVOM(digital volt-ohm meter/multimeter), when it has been disconnected from the harness. Keep in mind, diodes will only allow current to flow one way, so you have to check each leg twice, reversing the leads each time.