Report Charging system in 1963-64 Avanti Posted July 27, 2017 16 hours ago, Gunslinger said: If the car still has its original and correct alternator, it's a Prestolite 40-amp unit. Other Studes of the time used a 35-amp alternator unless they had a R-series engine. Because of that, they also used different voltage regulators. It's possible you have a wrong alternator, wrong regulator or both. Thanks for the reply. The alternator is not original. I don't know what it is. It was rebuilt by Studebaker Int'l. The voltage regulator is the one Stude Int'l sells for the car.