Butch,
The third relay in the voltage regulator is called the cut-out relay and it's suppose to open when the engine is turned off which opens the connection between battery and generator.
If this doesn't happen, the battery 'motors' the generator...turns it into a small DC motor and turn its.
This contact can weld itself shut causing this problem. I don't know if you can repair or file the contact back to life!
More knowledgeable folks will be along soon.
Stuart
