Ac not working

[macak]

Hi guys I'm new hire I have a problem I have seat leon 2006 1.9tdi tille yesterday everything was great today I went in the car start it up and put the ac the ac is not blowing any air and the small display that is on the dash board together with the buttons for to put the ac exs. auto,econ,up down nothing works but the fan for the ac that's in front of the engine is constantly working I checked the fuse nothing I unplugged the battery nothing (I heard about this honestly idk how long should the bat stay unplugged and then to plug it back) a 3 days before I change the housing of the coolant temperature sensor I suspect it is the sensor but I'm not sure any ideas will be welcome thank you all