I bought a 67 D100 pickup less motor and trans. The previous owner had converted it to a dual field alternator system. I hooked up the dual field alternator and it acts like it's not charging at all. I rev the motor and the needle on the dash and the aftermarket gauge both stay rock solid at 12 volts. I turn the lights on and it drops very slightly and revving the motor doesn't do anything. The needle never moves....not even back to 12 volts. I've tried a different VR and it acts the same. Is this normal operation for a dual field system? I know the alternator puts out a charge because I originally put a single field alternator in it and hooked up the blue wire by mistake...and it would put out 17 volts unregulated.