1990 240sx SOHC Air conditioning

[1sik240]

My air conditioning does not work correctly. I can turn it on and shift from hot to col and the level of the fan(1-2-3-4) and it works. However the little push buttons that switch it from the front vents to the defrost vent dont work. I push them and nothing switches. I have all the vents shut to try to defrost my wind shield and nothing happens. I have to keep a clean towel with me at all times. What could be the deal. The guy that owned the car before me said ac didnt work but it does to an extent. its col or hot just the above stated issue. he has removed a lot form the engine and I have no idea what. Except for the PCV valve which I am replacing this weekend.

[rcpautomtive]

I hope this will help their is a liitle motor on the drivers side by your feet on the heater box with a brown plug in that controls the doors for defrost feet and face vents eather the rod is missing that moves the door or the little motor that moves the door is bad I hope this helps you