[Dale_K]

The switch to recirculation mode is normal when you move the temp dial to its lowest setting. The Cruze alternator has a computer controlled strategy to avoid charging the battery when the motor is under load. It tries to do all the charging when you're coasting and this process means the system voltage goes up when you take your foot off the gas. The fan speed changes slightly when the voltage changes and you can hear fan change pitch. As far as I know it's totally normal for a Cruze. If you set the DIC to display the voltage you can watch the change on the digital readout and hear it at the same time in the fan speed.