Sounds more like a problem with the mode doors. Behind the control panel is a computer that controls the actuators. That is needed to provide the 10 percent air flow there, 20 percent over there, and 70 percent somewhere else. That gimmick adds a lot of complexity and unreliability to what used to be a simple common sense system, but that's what sells cars today.
I doubt the motor is failing. When they do, they usually fail to start up. They rarely fail once they're running. The fan will sound louder if multiple mode doors close to block air flow. If it seems like air flow is reduced I would suspect the controller first. I really hate throwing parts at a problem but there's no easy way to diagnose the system other than trying a new or used controller.
Friday, July 29th, 2011 AT 7:34 PM