1968 Ford Galaxie ALTERNATOR

what you have is a draw on the battery. the best way to check this is to put a test light one end to the battery and the other to the positive battery cable with it disconnected from the battery. Pull one fuse at a time to find the circuit that is causing the problem. When you unplug the voltage regulator there is one wire that goes to the starter solenooid. It is black with a yellow stripe. That goes to a 9 amp fuse in your fuse box that controls the hood light, dome light, courtesy light and trunk light. If you do what i said above and pull that fuse your light wil probably go out and it will be between those areas to look. I would go for the hood light or turnk light first. It should be a 9 amp fuse at the bottom of the fuse box next to a what looks like a 20 amp fuse. The light is staying on and draining your battery. it's kind of like "where is waldo, but only with a light" lol. You should be able to find it easily.