Alternator not charging

My alternator isn't charging now.

So I went through jrichker's write up on testing the charging system.

Everything was fine until I got to testing the voltage regulator with the key on. When I probed the green/red wire on the D connector at the alt, and grounded to the neg. battery post I got 12 volts instead of the correct ~2.5v at the green/red wire.

In the article it said your voltage regulator has failed if you read 0 volts. Why am I reading 12v here?

Does anyone know if the alternator is still the culprit?

Thanks.

I just said screw it and picked up a stock alternator at the junk yard. It fixed the problem.

At first I thought maybe the shaft was slightly seized up and after running the car causing the housing to heat up.
Turned out the alternator had a dead short inside.