2007 chevy aveo ac circuit

MY '07 Aveo has the wonderful feature of activating the AC compressor anytime the mode switch is set to defrost.  I know that this makes the the defrost system work more efficiently, but in the winter the car gets 100k less range per tank.  I don't want to disable the whole AC system, only the automatic defrost engagement.  Where is the switch located?  If I want the AC to work I'll push the AC button.  Does anybody have a wiring diagram?

Thanks

There is but doesn't it disable the whole system?  I just want to eliminate the automatic engagement only.   I need the location of the switch to remove it from the circuit.

Thanks

I am pretty sure that the relay is only for the compressor.  Try removing the relay and see if the blower motor and all controls work properly.  If that is the case, you should be able to get to the back of the relay socket and find the small wire that triggers the relay, simply cutting that wire and running both ends of the wire to a switch, this will allow you to turn the compressor off when you want to.