Performance Test
Updated by TSB 03-55-009A/C PERFORMANCE TEST PROCEDURE
Equipment and Instrumentation
The calibration of thermometers should be checked on a regular basis to ensure temperature recordings and test results are accurate. The thermometer can be checked by immersion into finely crushed ice. The thermometer should read 0 degrees C (32 degrees F). If the thermometer reads plus or minus, add or subtract this error to the reading on the gauge. The thermometer should be replaced if the error is 1.5 degrees C (2.7 degrees F) or greater.
The pressure gauge readings should be checked each time the manifold gauge set is used. Open the Hi and Low dial to atmosphere with the hoses disconnected. If the readings are plus or minus the zero kPa / PSI / BAR reading, the dial should be adjusted to read zero, or should be replaced. Once this procedure has been done, the pressure gauges will read zero for the day of use only, as they have been adjusted to the atmospheric conditions for that specific day.
Vehicle Settings
^ All doors should be closed, except the front passenger door to allow access to test equipment.
^ Engine hood cracked open, but not lifted. (This allows the manifold gauge set hoses to be routed outside the engine bay for viewing). If the engine hood is lifted, this will allow hot air to recirculate, increasing operating temperatures and pressures.
^ Vehicle should be parked indoors, out of direct sunlight.
Air Conditioner Control Settings
^ A/C switch ON
^ Recirculation mode selected
^ Fan speed at maximum
^ Temperature set to maximum cooling
^ Engine at operating temperature
^ Adjust engine speed to 1,500 rpm with A/C clutch engaged
^ Operate engine for 20 minutes
Performance Testing
The temperature output recorded with a dry bulb thermometer placed place in the center vent (vent closest to the blower) should meet the specifications shown.
NOTE:
If the A/C clutch cycles, take the reading before the clutch disengages.