We have the same problem. It sounds like a high pitch chirping sound. On our 2010 Fusion it happens when the heat is on and the fan is at the lowest setting. It does not occur all the time. Sometimes it happens just after we turn a corner other times on straight road. My wife can hear it from anywhere in the car. I cannot hear it unless I am next to the blower. Women tend to hear higher pitches than men sometimes. We have 6,000 miles left on the factory warranty, so I am getting an appointment with the dealer.
