elecronic troubles

Over the weekened we got my Duster running again, but there are a few electrical gremlins. At first the alternator was not charging the battery because the battery was only reading 12 or so volts and falling. So, we found a loose wire up by the coil that is for the alternator. The alternator is hooked up but this one was sticking out and it is now connected to the choke wire which is 12 volts. But now the battery is reading 17-18 volts. Acid was even leaking out of the top. Does anyone know what would solve this. We just think something is in the wrong place. When the engine was pulled 6 months ago we failed to take good notes on the wiring. Everything else seems to be good but this one problem. Any information would be greatly appreciated. Thanks