I know this has been covered before, but I can't seem to get the search engine to yield more than 50 results or results before 2010 (and yes, I did customize the correct time frame in the search engine).
At any rate, the 1938 voltage regulator originally had 4 posts but then went to three for the replacement regulator. To which posts are the three wires connected (generator and regulator) and what is done with the 4th (now superfluous) wire?