How can you tell if your voltage regulator is bad?

[Wheels of Terror]

How can you test your voltage regulator? How do you know that your regulator is bad instead and not  bad altenator? 

[Nacho-RT74]

-Ignition switch in RUN position and check for 12 volts between brushes wires...

However could it be also bad ground on chassis.

NOT completelly sure if still damaged regulator could send 12 volts and still damaged, even I don't think so. In 8 years never got a damaged regulator.

You can also unplugg regulator and ground the green wire brush and check if alt charges. becarefull since you will be getting max output from alt. If you get charge, then alt is working and regulator not... OR some of brushes wires are broken

To test alt:

-around 5-10 Ohms between alt brushes AND NOT CONTINUITY between any of brushes and chassis. That would be to check rotor and chassis continuity and isolation.

Then after that, check diodes and stator... would need to remove alt from car.