Headlight Mystery Saga

[forsair]

I have a 2010 Toyota Yaris Sedan. I have changed the headlight lamps about, what feels like, a million times myself. I drive a lot, the headlights are on when the car is in motion, that is just how I roll. My car is going on 282,000 miles. So I change out the headlights a fair amount. I now have a bit of a mystery.

Last Sunday my passenger headlight went out. On Monday I buy a new bulb. (Normally I buy and replace in pairs and this time I couldn't. So I only replaced this one bulb.) When I pull out the old bulb I noticed some strange stuff:

1. The clamp that holds it in place feels like it is now very rough, like it was exposed to heat.

2. The bulb edge one one side also looked like it had been exposed to high heat.

I replace the bulb as normal, and the low beam comes on, but it is dim compared to the older bulb. Also, now my highbeam indicator light is on. When I turn on the highbeams the indicator light gets brighter and old bulb works as normal, high beam comes on, new bulb. . .stays dim.

Because of work and afterwork meetings and obligations I can't deal with it until tonight. As I pull into home to evaluate the issue and decide what I need to try. . . my old "good" bulb dims to match the "new" bulb. High beam indicator light is still on all the time. When I put on the high beam, the "old" bulb gets to normal brightness for a low beam and the "new" bulb goes out entirely.

So. . . not going anywhere tonight. I'd like to fix it myself if I can. I'm not finding what issue the "high beam indicator" light coming on during lowbeam operation means.

Thoughts?

Thanks in advance!