Alternator/ regulator frusturating!

[LNeshem]

I tried wiring in a regulator from an 85 dodge 1/2ton pickup. It did not have any markings as to what post is what (2 posts). It is a small flat regulator about 1/2 inch thick and probably 4 inches square. I hooked up awire from each post on the regulator to the 2 small posts on the alternator. Then ran a hot wire to 1 post on the regulator just guessing here cause Not labeled and someone told me it didn't matter what post?? It charged but seemed to be charging alot, 15.5 volts. So quickly unhooked it and switched posts. Nothing not charging at all. Switched back to the way i had it first and Nothing, not charging at all this way either now?? I don't think anything burned no smoke or heat or smell? But now i can't get it to charge at all? For those of you that have successfully used an external regulator what kind did you use and what specific appliction was it for? Also did you use the black part that the factory has bolted onto the 2 small posts on the alternator and then has wires that exit that and go into the main wiring harness? By the way the engine is 99 24valve and it is in a chevy truck. Thank you in advance for any help!!
Lowell