Ventialtion Fan Problem

[ckios]

Geetings fellow Bmers. Can someone help?

I have a 2000 323i with 80k miles. I got in it last nite (after I had brought it back from the dealer from transmission replacement believe it or not) and the ventilation/cooling/heating system was acting up. When turn the engine on, the fan automatically goes to HIGH and adjusts on its own. I have zero control over the fan speed, even when am to push the control button in either direction.

Any thoughts? help...