96 Park Avenue Cabin Air directional control

My 96 PA cabin air directional control selector switch works fine for "High, windshield", "Low, floor", and "High + Low" but not for "Mid" select (dashboard louvers). In other words, the "Mid" select lights up on the display but no air comes out the louvers. This is particularly annoying when trying to get a quick cabin air cool down. Any tips or hints about troubleshooting this problem would be appreciated.

Try this:
Start engine and put blower on high.
Disconnect the vacume line connector from the HVAC programmer. Check for vacume at port 2 (violet line) supply from engine.
If no vacume check for leaks especially at the vacume tank.
Apply vacume to port 6 (blue line) and see if the air flow comes out the dash. If port 6 holds vacume but air does not flow from the dash, check for binding valve or actuator. If results are correct you need a new programmer.

I have a similar problem except there appears to be no control over the air, It just blows out the floor and the windshield (The speeds of the fan work OK). Do you think the answer you posted is the same as in my case? The dealer said he would fix it, but I would like to attempt to fix it myself (unless it is the programmable AC) how much would the programmable AC unit cost?

See thread under LeSabre for solution to this common problem