So a while ago, someone in a parking lot pointed out that only one of my four headlights was working. So I bought a few bulbs and got to work trying to replace them. Once they were out, I discovered that two of the bulbs were never plugged in; still not entirely sure why. So I plugged them in, and the one on the side with the already-functional headlight worked perfectly. So the headlights on the right side of the car worked, but not the ones on the left. Then I hit the dimmer switch, and suddenly all four headlights worked! A bit of research later, I discovered why. Turns out, the 1966 Thunderbird has two headlight control modules. One controls the high beams, the other controls the low beams. However, it seems that one of the previous owners of the car thought that one of the modules controlled the left headlights and the other controlled the right headlights. So both my low beams are on the right, and both my high beams are on the left. For the moment, I think I’m just going to leave it that way, since my headlights are dim enough that even with the high beams on, they’re not particularly bright. And now I can turn my left headlights on and off with the press of a button!
TL;DR: My car can wink.