A/c Fan

THE A/C IS BLOWING COLD BUT IT WILL ONLY BLOW OUT THE FEET VENTS. I BOUGHT A NEW A/C HEATER SWITCH DID NOT FIX ALSO CHECKED RELAYS. (1995 Z-71 V8):

I believe that you have a vaccum operated system. If you lose vaccum to the door actuators on the air conditioning box the doors are spring loaded and it will go into a default mode usually it is the defrost vents and the floor vents. When you replaced the switch was there vaccum lines attached to it? Chack make sure you don't have a vaccum line off somewhere.

there were no vaccum lines connected.