A 12 volt draw on battery from a one wire alternator

Thanks I have not found anything yet. Was overcharging and now I had alternator bench tested and was putting out 15 volts. Put it back on car and not charging the battery according to advanced. Car running only off battery. I've about pulled all my hair out with this thing. Wiring seems to be right. I bought a new regulator but did a test the manufacturer said to unplug regulator and run jumper from field wire to negative post and start car. If not showing charge it said not to hook up regulator. Should I change the ballast? Any ideas