97 T-bird AC Question

[Luminous311]

I'm new to these forums because I just bought a 97 Thunderbird LX.
As with 99% of used cars, there are problems. The AC blows cold, but when I set it to AC or Max AC, it will only blow out of the defogger vents.
On other settings, air will blow out of the foot-level vents, but air never comes out of the main, front-facing vents.

Summer's creeping up here in Arizona, so I'm hoping somebody can help me out with this issue. I'm led to believe it might be a leaky vacuum hose or a broken actuator, but I'm still pretty clueless. Thanks to anyone who can help!