[VetteVet]

The one-wire alternators have a special regulator inside which senses the system voltage from the large output wire that is connected to the battery and truck circuits. It is not as good at voltage sensing downstream from the alternator as the three wires which are wired correctly but it usually works ok to keep the battery charged.

If you unplug the three wire alternator it may continue to charge because the fields have some residual magnetism until the engine is shut down and it leaks off.

When the boys loop the small red wire from the no. 2 terminal over to the red wire it does the same thing only externally. If they use this method for the conversion from external to internal regulation. Again voltage sensing is not as accurate as when the no. 3 wire is connected to a junction located downstream away from the alternator.

There are also alternators with magnetized rotors that do not require excitation but their output is still controlled inside the alternator. They run about $300 bucks.