OK. Lets fix both and also clarify what the meter labeled 'alternator' shows.
The meter is an ammeter. It shows current flowing into or out of the battery. Why is it labeled 'alternator'? I really can't say? Maybe that labelling was introduced when alternators were introduced.
Anyway, battery charging or discharging also lets us know whether the alternator is working or not.
If the alternator is not working, the car will be running on battery power and you will see the needle swing toward discharge all the time. In general, the needle should be close to the center. Zero is a good thing (once the battery is charged).
Loose items to fix:
The green wire provides power to the rotor. The connector housing can be removed with a bobby pin (those still around?), a cotter pin filed, or the proper tool. Insert here.
View attachment 1715547018
To depress the tab or barb shown here.
View attachment 1715547019
Check the wire crimp to the terminal, and if need be replace it. If its Ok. might just need to tighten the rolled sides a little.
This one was not in the best shape - nore was the wire. Its from a harness that I retired but saved for reference and parts.
View attachment 1715547020
Worse case scenario, install a replacement. There is enough slack in that wire to do this if you cut the minimum.
View attachment 1715547024
Now as far as the male bolt goes, are you talking about this one, where the wire with a ring terminal attaches?
View attachment 1715547021
If so, if the threaded portion is loose, its best to open up the alternator and gently tighten it.
It's relatively easy to do on the squareback.
This is a critical connection, and loose can be a problem in two ways.
One is the obvious - won't get power output The other is that if it touches the housing, then it will be a short to ground. Its mounted in an insulator, so that is normally not a problem. But if the insulator is damaged, then replace it. Again on the squareback, this is an easy fix.
On the round back it is a little more difficult to access. On the roundback all the connections are soldered and the output stud also is combined with the filtering capacitor. So on that one, might want to let a shop fix it.