The airflow does comes out of the centre vents , then as the
dialled in
temp approaches, currently at 20C, the airflow diverts completely to
the
windscreen.
The air flow comes back to centre vents if the temp is reduced
further say
18'C
My guess is that one of the pods has a vacuum leak, and when the
ACC goes to actuate it the vacuum leaks away and the system defaults
to the defrost vent pattern. Maybe the footwell pod? Use a MityVac
on the lines coming out of the electric vacuum manifold behind the
ACC panel. (Or is it behind the glove box?)
-- Jim
