Climate Control has a mind of its own

I just bought a 03 LTZ which has duel climate controls. How come when I change the temp either for the driver or passenger the fan comes on? I don't want it to unless I turn it on!
Thx

That's what it's supposed to do. You tell it the temp you want and it gets the air to that temp. If you don't want the fan to come on, don't change the temp setting - leave the climate control off.