1966 dart problems, help

If that green wire that was never hooked up goes to the alternator then yes it could overchage. I would think without the field wire hooked up you may be throwing max voltage to the battery at all times. In your first post you said it was running at 17 amps? Did you mean 17 volts? You should measure somewhere in the range of 13.5 to 14.5 volts at the battery when running.