Recently on my 05 is 300 the ac fan has been randomly dropping to low (I always run in auto mode) and then back to whatever speed it was at. I didn't think much of it until today, when I got in the car and heard the worst high pitch noise. At first I thought it was coming thru the radio so I checked the antenna wires. At that point I discovered it was actually either the fan it's self or the controller unit. Attached is a video of the car making the sound. I wasnted to get some input before I just start replacing components. Pretty sure the controller is dying. What do you think?