Easy Fix? PIA Problem AC Air Flow

[nycnftm]

1st gen Exp. The a/c works but keeps changing where it blows air. I could be enjoying a cool breeze on my face and then it will go away from the dash and blow on the windshield for a few minutes, then back to my face, then to the floor. Can someone please tell me where the problem is?

 

[StephanSloan]

Any Chance you have a vacuum leak? Does the airflow change from the vent to the window when the engine is under load?