Originally Posted by GDC-SRT
I am not sure as to how, but there is a feature on these cars, If you push one of the heater buttons when the car is off, The heater will run for a time. It should reset automatically with next start. you may have activated this feature. look in the manual, it should explain.
That feature is actually pushing the "rest" button after the car is off to dry out/clean the system. This would not cause the fan to blow at that level though.