Here's a quick test- - - -
Run a straight 12 volt wire from the battery positive terminal to the "F" terminal on the alternator with the engine running. (Disconnect the 2-wire plug first) If the alternator is OK, it will go into full output. There is an aftermarket electronic regulator assembly that plugs into the back of the alternator and eliminates the regulator. I used to use that one when converting farm tractors to alternator charging from DC generators. Another alternative is to install a later-model internally-regulated alternator. Most of them can be used by simply installing a jumper from the battery terminal to one of the regulator terminals. The other terminal can be used for a "no charge" light if desired, but it's not really necessary.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!