New alternator vs. Old alternator

The ammeter on my CJ has been showing negative current since I bought it. With a bad battery in it, I could jump start the car, and it would continue to run. With a good battery in it, it wouldn't charge the battery. The battery terminals read 12.54 + or - .03 no matter whether the engine was runnning or not. So I took the alternator off (#7027) and took it to autozone to have it tested. It read like 17.5 volts output, but the bearings sounded like crap. He had a #7127 rebuilt for $29. The guy there told me the 7027 was externally regulated, and the 7127 he said is internally regulated. Does anyone now if this is the only differance? Do I need to remove my regulator? Where is that normally at? It sounds to me like my regulator might be what is really wrong with the charging system. In addition, my old alternator had ground and battery, as well as two terminals that I think were labeled s and r, which were hard to read, as it was pretty dirty. The new one has the ground and battery but the two small terminals are labeled 1 and 2. How do these correspond to the older ones?

Thanks for your help.
Doug

 

sounds like the old regulator was bad. short of butchering up the wiring, I would make a new harness for the alt.