After some time of operation the A/C fails to cool and a lack of airflow from the vents may be evident.
A large pool of water may also be observed underneath the car after it is switched off.
This issue is caused by incorrect factory placement of the A/C thermistor (or Evaporator Temperature Sensor)
The thermistor does not protrude far enough into the evaporator case causing an incorrect reading to be reported to the HVAC (Heating, Ventilaition & Air Conditioning) Module.
This means the evaporator is actually colder than the vehicle thinks it is and the vehicle continues to stroke up the A/C compressor causing the evaporator to fall below freezing point. This creates a sheet of ice across the evaporator core which subsequently restricts the airflow from the vents.
This incorrect reported temperature can be confirmed by observing the [EVAP_TEMP] P.I.D. on a scan tool at the time of the fault.
Once the vehicle or air-conditioner is switched off, the ice melts and forms a puddle out of the evaporator drain tube and normal function is restored.
The fix is to replace the A/C thermistor cradle with the revised type (Available from Holden Dealer)
On the left is the revised sensor cradle, which is clearly longer than the original cradle on the right.
The revised cradle positions the thermistor further into the evaporator which rectifies the incorrect evaporator temperature reading.
The evaporator temperature sensor can be accessed by simply removing the glovebox as shown in the video below.
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