5k A/C Mutiny- help?

[Robert W Obrien <rwo@u.arizona.edu>]

Good evening, listers,
My 5000CS Turbo decided to overrule my climate control suggestions. The
compressor works fine, cool air flows, what's the problem? AC only from
the defrost vents when "AUTO" is selected. Floor vents too. I think all
the parts, mechanically, are functional, because selection of "ECON" gets
air (uncooled) through the dash vents. Is this the "brain"? Well, it's
summer in Arizona and my faithful Audi is navy blue- I need to figure this
out. I do have the Bentley manual, but does anyone have any BTDTs? If so,
and it is electronics-related, anyone know a reversible way to overrule
the "closing door" in the dash which directs air anywhere but where I want
it?
TIA,
Rob