[mpumas]

There is a hot water valve for the heater on the passenger side fire wall in the engine comartment. When the heater knob is turned fully counter-clockwise it closes the valve and therefore no heat. It is possible that the mechanic disconnected the wire that goes to the valve so when it is closed, the heat control knob does not activate the valve. So there is no possiblity for heat during the summer. In the winter, he just opens the valve manually. The A/C is controlled by the push-button switch and there is no way to disconnect it unless he pulls the compressor clutch relay. Not a good idea because the airconditioner should be run for a few minutes every month to keep the compressor seals from leaking and to keep the windows from fogging up when it is cold outside and there is considerable moisture in the air and you are using heat inside.