I'm new to generators.

How do I determine if my generator is working properly or if it needs to be polarized?
I installed new gauges and had the battery disconnected. If I start the truck, the ammeter is basically not moving. Shouldn't the ammeter be reading more than 0 if the generator is charging the battery?
I had to charge the battery this morning because it didn't have enough juice to start the truck.

Thanks,
JD



1951 Chevy 3100 1/2 ton (1957 235, 4 speed, 411 rear)