The original switch only turned the working high beam on, and both low beams off, so I assumed both were supposed to be on with no low beams, but the one's leads were corroded. It must've been more broken than I thought it was. Haha.

It helps that I have a few vehicles here with 4-light sealed beam headlights. So that kind of thing is just everyday stuff to me. 🙂

Driving at night will be interesting the next time, that's a lot of light! I figured all 4 lights drew too much current and they alternated. My understanding is the headlights on the old GM style switches come straight off the battery with no fuse.

I think there may be a circuit breaker built into the switch. The best thing you can do for that setup is install a relay harness so the switchgear doesn't handle the full current of all those headlights.

https://www.amazon.com/4-Headlight-Wiring-Harness-Headlamp-Ceramic/dp/B06XJ771YQ

I'll look into this. A now former co-worker told me blowing up dimmer switches due to overloading is common on these old GMs. Guess Scotty's right, even old GM cars have electrical problems. Haha.

Also, if you look carefully at cars with the 2-headlight sealed beam setup you'll see that the low beam filament is kept lit along with the high beam filament when the high beams are engaged. So what you're seeing is really continuation of the same practice used with the older setup.

Actually it was a really big deal when the 4-headlight system debuted. At the time there were no federal lighting standards so all 48 states had to individually change their laws to permit it. 1957 was a transition year and some cars were equipped with different lighting depending on what state they were destined for. They were not legal in all states until 1958.

4 separate headlights seems to have been the style for a while. The early 90s 5-Series is the last car I can think of with 4 individual headlights, though those housings weren't sealed beams, they had replaceable bulbs in glass housings. Everything is plastic crap with a single, multi-filament bulb nowadays.

I definitely prefer glass headlight lenses, all my vehicles have them. (Either sealed beams or halogen capsules.) No clouding up over time, though of course there's always the possibility of road debris cracking it.

I do as well, they definitely age more gracefully. Only thing I hate is they're expensive, I paid $40 for the sealed beam high beams. I was gonna get all 4 new, but $80 for lights when my low beams are still good was too much, haha. Do those old lamps lose their brightness as they age, or are they more ore less the same until they burn out?

$40? Mine cost $7 each.

$9

Well I ripped myself off. Haha. Sylvania's at AutoZone were $19.99 a piece. Never again. Haha. Those lights better last a while.

Sylvania is garbage. The guy at the store said that sometimes they burn out after a few months. Mine lasted about 280 hours. It was rated for 850h.
The GE headlamp that was in my van when I bought it, is still there 5 years later, burning brightly.
The Philips replacement I bought is still there, doing well. It's rated for 2,000h.
Read the ratings on the box. Avoid Sylvania. Their ratings mean nothing.

Great advice here.

I'll keep that in mind. I don't have high hopes for these, I saw on the bulb after I opened them they're Hencho en China. I think one of the bulbs was original, it said Made in USA and had no other label. It still worked, actually.