System and method for diagnosing the operation of air conditioner systems

Abstract

A microprocessor provides a diagnostic capability, and includes tables of acceptable values of parameters, such as air discharge temperature, suction pressure, etc., for different automobile makes and air conditioner types; provision is made for adjusting the acceptable ranges of such values due to one or more ambient factors, of which ambient relative humidity may be one. The microprocessor, after determining whether the air conditioning system has a cycling or a non-cyling clutch and providing a valid set of actual system values based on whether the clutch is cycling or non-cycling, compares actual values to acceptable value ranges of the air conditioner operating values, and displays possible causes of air conditioner malfunction on a video screen. Self-testing of both the microprocessor and associated electrical elements, and of mechanical elements such as conduits, valves and a scale is performed. the operator may command the microprocessor to display, in smaller print, a relatively large volume of detailed instrucitonal material dealing with specific checking procedures or repair. An air conditioner charging station withdraws refrigerant from an air conditioner, reclaims it by removing certain materials, and returns the reclaimed refrigerant to the same air conditioner from which it was withdrawn, and also provides new, make-up refrigerant to the air conditoner, in the amount necessary to make a full charge.