Auto Air Conditioning & Heater Repair: Buick PA 1995 AC blower prob, vacuum leaks, vacuum mode

Question
1995 Buick PA (not Ultra) blows A/C air out defrost vents only.  It started several months ago by starting out this way but after 5 minutes it would slowly changes to front vents.  Now it rarely changes direction no matter how long it runs.  Is it most likely the mode control motor or a vacuum issue?  I'm handy with a screwdriver, but is this for a Buick tech to handle?

Thank you

Answer
The 1995 Park Ave has an electric blend door actuator and a vacuum mode door actuator with vacuum reservoir I do believe.  Typically if the system is defrost only it has gone into default mode for operator safety (defrost only).
 The first thing is to check for vacuum leaks.  I can help you out with this diagnosis step by step if you like.  You may need more than just a screwdriver....

First thing to do is follow the black vacuum line out of the firewall to the vacuum source.   I will check in the moring where this is exactly as I can not recall from organic memory.  Message me back if you are interested in corresponding.

Wayne