[steelybill]

I guess he could unplug the alternator, and the ground for the light would not be there (??) The # 1 terminal on the plug is the ground path for the light.
If the light stays off with the plug out, it narrows it down the the VR I would think.
There also is usually a diode in the wiring behind the panel, but if that one were shorted, the engine would likely run-on or diesel a bit.