Oldsmobile/Buick Repair: 1998 Buick Lesabre Limited, climate control unit, electrical actuators

Question
My 98 Buick Lesabre's automatic climate control unit works great - except for the airflow level.  It seems to be stuck on 1/2 floor and 1/2 windshield.  No adjustments seem to change this - level (LCD display works), AC on or off, heater, vent, recirc. or front defrost.
No complaints with the system otherwise.
Thanks in advance.

Answer
Hi
This system uses 1/2 vacuum and 1/2 electrical actuators for air flow.
I would suspect a vacuum leak between the engine (the port for vacuum is on REAR of engine, upper intake, where the brake booster vacuum line is. the Vacuum line is "piggy backed" on the booster line).
If you could follow this small vacuum line and eithe listen for a leak (will be a hissssing sound) or actually see a break, I am sure that will be problem. The line travels into the passenger side compartment, and attaches to the HVAC Programmer which is under passenger side, under glove box area.
There is a possibility the programmer MAY be at fault, but I would check ALL vacuum to it first.
I Hope this helps
Good Luck
God Bless
Pawl