Electrical question about alternator

[quick72toy]

Have a question about the CS144 alternator.
I have a bunch of old alternators sitting in my garage and want to test them to see whats wrong with them.
I have read that we have a "B" style circuit voltage regulator  where one brush is grounded inside the alternator, and the voltage regulator control the positive power to the other brush which connects to the rotor coil. Controlling the positive power into the rotor coil  allows you to turn the alternator on and off.
 I also read that I can put the alternator into "full field test"  where it bypass the voltage regulator, by supplying battery voltage to the "field"  terminal.  If the other internal components are good his will cause the alternator to go to full charge mode.
Has anyone heard of this?
I'm trying to test the internal components. I can check the resistance on the stator and rotor, and check the diodes on the rectifier, but I don't know of any way to physically bench test a voltage regulator, so I thought this "Field mode" test should do the trick. So far after trying it on 3 different alternators it hasn't worked, and all the other internal components have checked out okay?
Open to thoughts ideas.
BTW I have a couple of stock 120A alternator as well as a few 140A Impala alts

Thanks,
Paul

[PacecarTA]

connect 12v wire with  lamp (194 bulb) inline across the L pin ,  the feild will activate  and maintain ~14.2v(varies with temp) . if it works properly the lamp will go off when the alternator is running 

now if you also run a power feed to the S pin  and it is higher or lower than 14.2v (but not 0v) the regulator will increase output voltage until the voltage   S port voltage reads 14.2v ,
 thats how a volt booster does its thing,  it drops the voltage to the S terminal which causes the output to increase above the std 14.2v

[quick72toy]

Thanks for the info.