the air con comes on if you have any of the heater controles turned on to the orange /yellow markers on the heater controls even if you dont have the aircon switched on these cars are designed to run warm you could also try getting a cpe deflector pannel to keep charge temps down what are your charge temps running at and do you have a constant stream of water in the charge cooler tank

the scn gauge does read the temp at the ack of the head so the water temps are abut 10degrees lower