In cold weather when operating in the "Auto" mode, our '03 will leave the fan off for several minutes after startup. Then as the coolant temp begins to rise, it will turn the fan on to low, then medium, then high speed. As the interior warms up, the fan speed will gradually diminish and end up back at low. You should be able to override this behavior by deselecting "Auto" or by pushing a button on the fan speed control.
This process takes a fairly considerable amount of time, perhaps as long as 20 minutes. In addition to fiddling with the fan speed, the system will start out directing all the air to the footwells and then finally add in the dash vents when everything's nice and cozy. On occasion, I've also seen it select "Defrost" on its own.
IMHO, this is a very sophisticated system which performs much better than the auto climate control on our 2000 BMW 528. I can hardly wait to find out what surprises it has waiting for me in hot weather!
-Karl
|