I drove the car for an hour or so with no problems. After awhile when I went to start it again the red light came on.The battery tests 12 volts when running and should be at least 13.5. I swapped out a different voltage regulator but that made no change. The electric shop said the generator was fine they just cleaned the armature( could they be wrong)? The Field wire and other wires appear to be connected properly. The fan belt is tight to spec? The generator appears to not be charging. I'm baffled? Anyone have any ideas?