Automotive Air Conditioning Information Forum

So I have a 2012 scion tc. The AC in the car is blowing warm air or lukewarm, pretty much whatever the temperature outside is. So I took it to a shop to be looked at. They said it had a charge. They checked all the fuses and relays and they were fine. They put in new AC amplifier and AC switch. None of that worked. BUT they said they can make it work and blow cold with a scantool. Then they wanted to 'try' replacing the drier and evaporater. I said no. This is costing a lot of money and I don't want to do trial and error with my money. So I took a look myself and noticed that my ac compressor clutch is engaged, always, it spins whether the AC is turned on or if the air is turned off completely. I guess it's stuck? But why? What is controlling it? And if it's stuck engaged, shouldn't it be 'stuck' in 'AC mode' and be blowing cold air constantly?

Any thoughts??
Thanks

If they can make it blow cold with a scan tool, then the refrigeration circuit is working. You don't need an evaporator or drier. You can purchase the service manual on a CD for this vehicle and have all the service info for the entire vehicle. You can have a defective sensor; the manual will help locate the problem. Do not just throw parts at it; find the problem. Sorry I can not be more help.