regulator?

Try connecting a volt meter across the battery and note the reading, should be a little above nominal battery voltage if fully charged. Start engine and increase revs to fast idle, meter should show about 14.7 volts if charging is good,(with 12volt system) wether you have generator(dynamo) or alternator.
A sticking regulator with a dynamo can result in the dynamo trying to run like a motor and drive the engine, resulting in a flat battery as well as getting hot and can also burn out the regulator.
Hope this is of some use.

Mr. Toad
August 2008