High Voltage

1) Measure the voltage at the +12v wiring going into the VR (normally blue) and see if it is close to the voltage at the battery. If not, then it is a wiring or voltage drop issue to the VR that needs to be fixed.
2) If it is good then, remove the green filed wire from the back of the alterantor and see if the battery voltage drops to the 12v range and stays there or slowly drops even when the egine is revved.
3) If the voltage drops in 2), then try another VR. If the voltage does not drop, then the filed or that filed brush is shorted to the alternator case and is casuing a constant full tilt charge.