[petek]

Off the top of my head, I believe that in an alternator with an external regulator, the regulator is required as it sets the field winding current (and there-by adjusts the output voltage).

How do you know that the battery is not being charged? Do you have an ammeter on your dash? My thought here is that if you believe the battery is not being charged because the battery is discharged every morning, you might have something drawing current from the battery all night (rather than a charge problem).