Park Avenue heater/AC problem

The problem I'm having is cold air out of the driver's side center
vent when set to mid-range temperature, e.g. 75F. If I run the set
temperature way up, e.g., 85F, it will route all air to the floor, and
it's warm. I've confirmed vacuum to the system, and the coolant hoses
to and from the heater are warm.

I have been searching old newsgroup postings and gotten several leads,
but so far nothing has worked. One or two people have suggested an
error display sequence i.e., simultaneously pressing Off and Warmer
buttons to get codes to show up on the display. However, this doesn't
work on my car.

Also, someone said to momentarily disconnect the battery in order to
cause the AC programmer to reset. No help.



Any other ideas?



Thanks.



Ed