Refrigerant System Performance Test

WARNING: This page is about a different car, the 2004 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.

Inspect the refrigerant pressure. REFRIGERANT PRESSURE CHECK .
Place a dry-bulb thermometer in the driver-side center ventilator outlet.
Start the engine and after it is warmed up, run it at a constant 1,500 rpm .
Set the fan speed to MAX HI.
Turn the A/C switch on.
Set to RECIRCULATE mode.
Set the temperature control to MAX COLD.
Set to VENT mode.
Close all the doors and windows.
Wait until the air conditioner output temperature stabilizes.

Fig 1: Placing Dry-Bulb Thermometer In Driver-Side Center Ventilator Outlet
Courtesy of MAZDA MOTORS CORP.

Stabilized condition
- The A/C compressor repeatedly turns on and off at regular intervals.
After the blower air is stabilized, read the dry-bulb thermometer.
Verify the ambient temperature.
Verify that the temperature reading is in the shaded zone.
- If the there is any malfunction, inspect the refrigerant system according to the troubleshooting chart.
Fig 2: Center Ventilator Temperature Vs. Ambient Temperature Chart
Courtesy of MAZDA MOTORS CORP.