My 2002 fan makes a flutter-vibration sound which comes from the passenger-side vents both high & footlevel (depending on setting). It sounds like a leaf is in there someplace. Has anyone had success in dealing with this problem?

 

Start taking things apart. The vents just pop off, the air intake is at the base of the windshield under the plastic which come off, and the fan motor is accessable from the engine compartment. The rest is all up under the dash. Get one of those dentist/flashlight things, and look around.

 

Thanks for that info, I can have a look.

 

As it turned out, my squirrel cage fan had about a dozen small oakleaves in it. When the fan was set on low, they just sat on the bottom and caused no problem, but higher speeds flung them up against the blades, blocking the air. Interesting, and easy to take care of on my own.