As our own Jason Torchinsky would love to tell you, when sequential turn signals appeared on the 1964 Ford Thunderbird, it was major moment in the history of indicators. Unfortunately, as I’m sure you’ve heard, Jason is no longer around to tell you anything about it. The basic sequential light idea spread through the Ford lineup and into the Mopar lineup, and again, as I’m sure Jason would or would have been happy to tell you, changed the way we think about vehicle lighting forever. But have you ever thought about how they worked?

Where modern sequential lights are digitally controlled, the old ones were electromechanical. A little cam turned, and contacts uh...contacted, illuminating the individual bulbs in a sequence like a little music box. (Ok, it’s a little more complicated than that, there are some solenoids, etc.) But here, take a look:

How cool is that? Listen to how loud it is!

Depending on how your brain works, this is either bafflingly complex due to the number of interdependent moving parts or wonderfully elegant due to the lack of invisible computer controls.

I tend to love stuff like this, where if it fails, you can see exactly where and how, and ideally effect a quick repair.

Here’s the same effect on a 1969 Imperial

And here’s what it looks like all pulled apart:

Look at that! There’s absolutely no question what’s happening. I’m sure that even someone with an average brain like me could figure out how to make this stuff happen with a Raspberry Pi or whatever, but there’s just something about watching that little motor turn it’s little clicky cam to make those little clicky contacts. Wonderful.