2002 S60 169K -- high mileage but very well maintained!

Background: About 300 miles ago my instrument cluster died (no light, no needle movement, SRS airbag warning). I removed it and sent it to:

https://europeanelectric.net/

Who did a good job getting it sorted. Similar to but cheaper than Xemodex. No problems since.

Tonight, I start up the car, the instrument cluster is dark, and the rest of the interior lights (e.g., steering wheel, climate control) are very dim, and the radio is pitch black. After 3 seconds, the instrument comes on, normal. Everything else remains black. But everything works. Radio works. Climate control. Heated seats.

After driving about 10 miles, everything came back on, nice and bright.

I stopped to buy some beer, came out, restarted the car, and everything was dark again. They remained so for the next mile of driving.

I should add that sometimes the light dimming dial does not work. I should also add that in May, the alternator went out, killing the battery, and giving me an "overvoltage" warning. No real problems since, but I have fear that the high voltage caused damage.

I looked around on the internet and couldn't find anyone else writing about a similar problem. Lots of dark or non-working radios.

Please help!

 

Follow-up.

After some more digging on the internet, this sounds like a headlight switch failure. While the lights are dim, movement of the headlight selector does not work, nor do brights turn on. The rear foglight switch does not turn on the light. And the gas hatch button does not disengage (meaning, of course, one cannot put fuel in the car).

Can anyone confirm or advise?