An air conditioner system for sensing and controlling the temperature in the compartment of an automotive vehicle to an established desired temperature includes an over-correction means whereby the vehicle compartment temperature is temporarily increased to exceed the desired temperature and the temperature rise is terminated after the sensed temperature has attained or nearly attained the desired temperature. When the sensed temperature rises so that the difference between it and the desired temperature exceeds a reference value, the corresponding correction signal is generated and correction is applied repeatedly so as to make the difference less than the reference value and thereby to attain the desired compartment temperature.
