So I am having a similar issue on my '82 244....

My heat and A/C both work fine, it's just that the push button selector has no effect on anything. Most of the airflow is stuck on the floor, with a little blowing from the defroster and also the face vents.....so maybe everything is open? I don't hear any leaks anywhere, and I currently have the console out along with the glovebox and under access panels because I'm also working on electrical issues. I can see that all of the actuators are hooked up and move freely by hand, all of the hoses seem supple and not worn out, and I can see the "tennis balls" behind the radio. But I don't really know what I'm looking for. I can see all of the hoses going into the selector panel, although on one side there is a cap in place.

Can anyone suggest on where to start looking first? My first thought was bad selector panel (electric issue) , but after looking behind it, it looks purely mechanical with the springs sitting there.

Thank you!