A/C only blows out of floor vents, how to fix?

[j.edi]

Is there a servo somewhere under the dash perhaps? I thought it sounded like the flaps were struggling to change position a few months back, now all I get is floor - no matter what I have the fan direction selector dialed to.

ps. I changed the blower motor/fan/resistor/relay last winter, so it's pushing air like a champ - just not where I want it to anymore. It worked fine for months after I replaced all that old junk, so maybe I just need to replace another old part somewhere now?

1995 GMC Sierra 4.3 V6 (VIN Z)

 

[90halfton]

There's a motor underneath by the gas pedal sorta that controls that. There's. Also linkage that turns the vents that sometimes comes off