[Excaliber]

The regulator itself needs to be 'excited', usually with a 12 volt source that often goes through your 'Ignition' light. If the light itself doesn't work it could be as simple as a burned out bulb. THAT would not allow the 12 volts to turn on the regulator.

Using a volt meter you can check the regulator terminal to see if it has 12 volts when the key is ON. I THINK the terminal is marked "I" for ignition.