The center button on the ACC control on my '82 300D (W123) is dead. As in, push the button and nothing happens--no blower motor, no compressor kicking on, nothing. The A/C functions with the 2nd (from the left), but only blows out of the two outside vents and the defrost vents.

Is there a way to repair the electrical part of the pushbutton ACC control panel? This seems to be an electrical problem to me, but could there be a vacuum fault as well?

I've looked through the archives for the last couple of hours, and didn't find anything specific to this problem. I'm looking for the most cost effective repair that will get my center vents blowing again. I haven't taken anything apart yet, and want to be as educated as possible before pulling the dash apart.

Cheers,

Brad