How do you have your meter setup? Since it's not too complicated of a circuit, and we want to know what voltage is at the connecter, you should have the black lead to ground. Sticking it on the negative battery terminal is ok.
I assume you have the connector pulled and are testing the wiring on the connector? Are you testing these with the ignition turned on or off (with the car not running)?
If we are looking at the alternator from the drivers side looking into the alternator connector here's what the three terminals do:
LH Vertical: "IG" or ignition. This is power from the ignition switch to "turn on" the alternator. With the switch on you should measure battery voltage at the connector. If you don't, there is a fuse that should be checked and then wiring.
Middle flat: "S" or sense. This is the feedback from the battery that lets the alternator know how it's doing. If the voltage is too low it will crank out more, too high it will output less.
RH Vertical: "L" or lamp. One the alternator output is low enough this allows the dash light to come one. We won't worry about it right now.
With the negative lead on the battery, test the voltage at the wiring harness connector. Mainly look at the S and then IG with the ignition switch on and off. Check that the wiring is in good shape and the copper connectors look clean and have a wear pattern where they have been making contact.
Also, just because you got a reman alternator doesn't mean it was actually rebuilt. The reman auto parts business is pretty shady. I've seen people go through multiple "reman" alternators until they get one that works.
More reading:
https://www.electricalrebuilders.org/er ... nators.pdf