80 amp alternator is it supposed to be in real free or supposed to have a lot of resistance
There should be some resistance but not enough to stop you from cranking it by hand. If not the wiring or the bearings are bad. In which case it’s probably time to look at a new one.
HUH? Resistance to turning? No, should turn easily with the belt off.
Or electrical resistance across the terminals? Depends on what terminals you tested across.