Dashboard squeel - 190e 2.6 (1992)
 

A load squeel has started comomh from behind
the glove box.

What could the noise be?

Sounds like a spinning objedct that is loose. Perhaps lige a fan belt that is loose 9has been stretched).

Sounds like the small sampler motor for ACC system cabin temperature sensor.

Do a search on this site for "little electric motor/fan behind the dash"

Not an expensive repair and easy if you have a glove box.

little electric motor/fan behind the dash was the issue
 

Yes, I have found the issue - the little electric fan specifically behind the right (passenger) air vent.

I removed the glove compartment and the air vent cover, and teh little motor was easy to access and remove.

now to purchase a new one.