[65comet]

It should be under the passenger side dash. There should be a large plastic box under most of that area. I'd look for a metal arm that comes out of it that is connected to a cable. Then I'd try moving that arm from there while at the same time moving the control to see if they are connected and that you have the correct arm for the temperature and not one that changes direction of the air, such as from the floor to vents or defroster.