if you cant change the directio of air flow, like vents to floor or to defrost. check for a busted vac line.

follow the one off the top of the sc to the fire wall. it runs down the fender and under the fuse box then into a wire harness and into the cars cab.

this line is what powers the air flow actuators, all vac powered.

hot and cold air is the blend door actuators. those are electric.