Ok, so everyone agrees this little roller switch / control guy is the instrument cluster dimmer control.
Question is....How the heck do I get in behind it and see why it doesn't dim anything ? You know I'll start prying this plastic construct apart, snap a few pieces off, then spend months touring the local junk yard to find replacement parts in the right color.

Please tell me there is a trick to taking this whole center heater vent thing apart. You press right here, and it all just pops open, right ?

I found two screws just underneath this roller switch and the pushbutton switches for hazard and rear defroster. Opening my eyes helped. I'm getting closer...