You see I'm going to continue operating under the assumption that it works in precisely the manner that my grandfather, the previous owner of the car for 25 years, told me that it worked. He had quite obviously reset it prior to it coming into my possession, so it was working relatively recently.
Since I know for certain that he had made it work, and I have no reason to believe that it stopped working one way and started working a different way all on its own without any cause, I'm going to stick with the logical assumption that it works the same way it always has and that I simply don't have the tool required to make it work.