Chevrolet: 1990 Camero, dash vents, pluged

Question
I know you work mostly with older vehicles but thought I would ask any way, I have a 1990 camero with an air conditioning problem, air only blows out the defrost vents and not the dash vents and it is hot air, why would air not blow out the vents.  

Answer
Angie ;
 Hi and the air should blow out the vents , have you checked to see if the vents are in the open setting, and  check if any vent ducts are loose or open or un pluged .
and see if the switch is in the proper setting for the A/C.
and as far as the hot air ,you might need some service or a re-charge to the system   ..