Mazda MX-5 NA silhouetteMX-5 NA

AIR CONDITIONER

U-34prose procedure
Continued from U-33

On-vehicle Inspection

Thermoswitch

Thermoswitch on-vehicle inspection

  1. 1
    Remove the glove box.
  2. 2
    Run the engine at idle.
  3. 3
    Turn OFF the A/C switch and set the blower switch to the highest position to operate the blower fan for a few minutes.
    Detail view of the A/C control panel rotary fan-speed switch and A/C button. The fan-speed knob has positions OFF, 1, 2, 3, 4 with a fan icon. Below is the A/C push-button with ON indicator. Illustrates step 3 of setting the blower switch to the highest position.
    05U0UX-057
  4. 4
    After a few minutes, turn OFF the blower switch and stop the engine.
  5. 5
    Disconnect the thermoswitch connector and check for continuity between terminals of the switch.
    Under-dash view showing the cooling unit installed with the thermoswitch connector being disconnected; terminals 'a' and 'b' of the switch are labeled. Illustrates step 5 of disconnecting the thermoswitch connector for the continuity check.
    05U0UX-058
  6. 6
    If not as specified, replace the thermoswitch.
    The thermoswitch contacts will be open if the evaporator temperature is below 0°C (32°F).

Thermoswitch continuity (on-vehicle)

a—b
ContinuityYes

Inspection

Thermoswitch

Thermoswitch inspection

  1. 1
    Immerse the sensing bulb in a container of ice water.
    Bench-test setup for the thermoswitch: the sensing bulb is immersed in a container of ice water, and an analog ohmmeter / circuit tester is connected across terminals a and b of the switch to verify continuity at 0°C (32°F).
    05U0UX-059
  2. 2
    Check continuity between terminals of the switch as specified.
  3. 3
    If not as specified, replace the thermoswitch.

Thermoswitch continuity (bench test)

a—b
TemperatureAbove 0°C (32°F)
ContinuityYes
a—b
TemperatureBelow 0°C (32°F)
ContinuityNo

Evaporator

Evaporator inspection

  1. 1
    Check the evaporator fins for blockage. If the fins are clogged, clean them with compressed air.
    Never use water to clean the evaporator.
    Detail view of the evaporator core with its fins and outlet pipe visible. Illustrates inspection of the evaporator fins for blockage.
    05U0UX-060
  2. 2
    Check the fittings for cracks and other damage. Replace the evaporator if necessary.
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