Volvo Repair: air condtioner, air condtioner, key switch

Question
I have a "88 240. Everytime I turn the engine on the compressor kicks on, no matter where the a/c knob is set. Is this right or what could the problem be? Thanks

Answer
Hello Brian,  If you are not the original owner check the wiring.They may of by-passed the 'low pressure safty'switch.it is on the reciever/dryer,two green wires.Also check the wire comming out of the comp.clutch,it may be wired direct to current with key 'On',that is terminal 15 at the key switch.Thank you and good hunting! PKD