Mazda MX-5 NA silhouetteMX-5 NA

AIR CONDITIONER

U-30prose procedure
Continued from U-29

Charging (continued)

  1. 4
    Charge the system with the specified amount of refrigerant.
    Manifold gauge set with both gauges visible, connected via hoses to a refrigerant container shown at the bottom, illustrating step 4 (charging the system).
    05U0UX-048
  2. 5
    Close the low-pressure manual valve and the service valve of the refrigerant container.
  3. 6
    Carry out a performance test (Refer to below).
  4. 7
    Stop the air conditioner and the engine.
  5. 8
    Quickly disconnect both hoses from the gauge fittings.
  6. 9
    Put the cap nuts on the gauge fittings.
Specified amount
800 g (28.24 oz)

Performance test

After finishing repairs, conduct a performance test of the air conditioning system as follows.

Performance test

  1. 1
    Connect the manifold gauge set. (Refer to page U-28.)
  2. 2
    Start the engine and keep the engine speed at 1,500 rpm.
  3. 3
    Operate the air conditioner at maximum cooling.
  4. 4
    Open all windows and doors.
  5. 5
    Place a dry-bulb thermometer in the center ventilator outlet.
    View of the instrument panel / dashboard interior of the MX-5 showing the steering wheel, center console with audio unit, and the center ventilator outlets. Illustrates step 6 of placing a dry-bulb thermometer in the center ventilator outlet during performance test.
    05U0UX-049
  6. 6
    Place the wet-bulb thermometer close to the blower inlet.
  7. 7
    Wait until the air conditioner outlet temperature stabilizes.
    When the high-pressure side becomes too high, pour cool water on the condenser. If it is too low, cover the front of the condenser.
    Manifold gauge set shown alongside a thermometer scale on the right, illustrating the stabilized-condition gauge readings during the performance test.
    05U0UX-050
  8. 8
    After the air conditioner stabilizes, read the dry and wet thermometer at the air inlet.
  9. 9
    Calculate the relative humidity from the chart below by comparing the wet- and dry-bulb readings.
    Psychrometric chart for reading relative humidity from wet-bulb and dry-bulb temperatures. The x-axis is dry-bulb temperature in degrees Celsius and the y-axis is relative humidity (%). Diagonal lines represent wet-bulb temperature isotherms. An explanatory text panel at the top-left titled 'HOW TO READ THE GRAPH' describes the example procedure for finding humidity from wet/dry-bulb readings.
    05U0UX-051
Blower inlet temperature
25—35°C (77—95°F)
High-pressure side
1,177—1,619 kPa (12.0—16.5 kg/cm², 171—235 psi)
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See also

U-28AIR CONDITIONER

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