Previous to owning this 1990 300E I had 1988 260E and what I noticed is that the fan in the 1990 just keeps blowing when left in the auto position even when the temperature in the car has reached that indicated on the selector wheel. With my 1988 the fan would slow down as the desired temperature approached i.e. it was more responsive to the temperature inside the car. Anyone have any clues at to what could be going on here?

Thanks.