One advantage of 1980s cars is there is no "check charging system" except a voltage meter in the dashboard. My 911 did not have one originally but I had one added to my Tach so I know the voltage now.
I can change the alternator in the Elky in 20 minutes. The 911 is a bit more involved.
Hopefully your car is not one like so many modern cars with the alternator under the intake manifold or some other hard to get to place.