Why does my AC only blow out the window defrost vents?

[97 B/W GTS]

It worked fine 2 weeks ago. I have the knob pointed to the snowflake and it only blows at the windshield. It was 100+ here and I sure miss the cold air blowing at me.

Any ideas?

 

[98viperGTS]

Almost sounds like your selector is not working correctly. Have you tried to select other settings to see if they are working as well?

 

[dave6666]

Has the vacuum line at the intake manifold or over by the A/C unit come undone? Small black nylon tube.

 

[97 B/W GTS]

98: Yes, I tried all knob settings. Same result.
Dave: Thanks. I'll check the vacuum lines.