14 GA or 16 GA Fusible Link?

I installed the new 16 gauge fusible link and the '65 Valiant is up and running again. I found a common "fault" when checking charging voltage which is I need to rev above idle speed before the alternator begins to show a charge. I found that same anomaly in my '72 Satellite.

The initial problem with the Valiant is that while idling one day it just stopped running and every single electrical component in the vehicle went dead at the same time.