95 buick park ave. one sided heat/ac

[kitkatviv123]

I have a 1995 Buick Park Ave. It has climate control on passenger side. This summer when I turned on the AC the drivers side got cool but most of the time the passenger side was hot (the climate control button did not help). Sometimes it did get cool though. Now that is winter it is doing the opposite. I have heat on my side but not the passenger. It has worked one time only. Any ideas on what could be wrong. Hopefully I can fix it myself.
If so, HOW?

 

[kilovolt]

Flap not opening / Tube fallen off check behind air vents

 

[kitkatviv123]

Due to recent surgery and the cold weather (with no garage) I have not been able to do anything. I just wanted to say thanks and I will let you know what happens.