The air conditioning in our 1993 Toyota Camry isn't working correctly. It almost sounds like there's something blocking the air ducts before it gets to the vents on the dashboard. When you turn the air on, you can hear a "flump" sound like something's being sucked onto a duct opening by the airflow (kind of like when you hold a piece of paper to the back of a fan and it sucks onto the fan).
Does anybody know what might cause this? The mechanic quoted $200 (said the entire dashboard had to be taken off) and my mom said he said something about about a "cluster arm"--which according to Google is a weapon from Final Fantasy....

Is there something else that could be malfunctioning that sounds like "cluster arm"?