charging/alternator help needed

[hollywood68]

This may be long but I figure its better to give all the info I can so hopefully someone can help

So the truck sat for a little bit, maybe two weeks, while I did some suspension mods. Went to start it and it wont hold a charge. First I found one of the terminals on the back of the alt had come off. Hooked it back up and checked to if the alt was putting out a charge, and it went up about .5 volt (from 11.5 to 12). Noticed a couple wires need repaired, could be arcing from the bad connection, not sure.

I pulled the alt and took it to PepBoys to get it tested. They tested it three times and it passed each time. Out of curiosity I had them pull a alt for an 84 Trans Am, the one mentioned in the internal regualted swap thread, and compared it to mine...they are the exact same. Even found the part # on mine that confirmed it.

Now I know I have several things I need to do, but I am confused as it looks like I have an internally regualted alt but all the wires to the external voltage regulator are still hooked up. Im assuming this is not good, but I have been driving the truck for 5 months and it was fine until it sat for the two weeks.

Any help greatly appreciated