Well if it blows out at your feet you know the blower is running (as it's a common problem for blower motor shaft to rust up from AC condensate drain plugged up) but in your case it sounds like the air diverter damper arm actuator is broken or just stuck (yes it can rust too) you'll need to remove toe space cover to gain access to it on passenger side floor move heater contol back and forth to watch it move Or (NOT) you may have to free this up or replace it