Mechanics

THE DETAILS ARE IN THE DETAILS FEILD

2005 Chevrolet Optra

HiI have an Optra-Forenza-Lacetti, 2005, 1600cc
Lately I've made some repairs to the AC system that included replacement of the following:
Dryer, High pressure valve (plugged inside the compressor)
High pressure pipeline

Now what happens is:
At low fan speeds (1, 2) the systems freezes up. After 30 mnts of driving poor airflow + high temp in the cabin.
At high fan speeds (3, 4) everything is just find except that I suffer a very cold air hitting my face (colder than what I'm used to get b4)

What I do to solve this is turn the compressor off till the ice melts down then turn it back on

Thanks a lot for your help
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Essamshawky
September 24, 2012.




The thermosensor circuit is not working correctly and this resullts in the cooling coil icing up. Recheck the thermosensor location and installation. Try turning the temperature to a higher setting.


KHLow2008
Sep 24, 2012.
Thank you
Can you please explain what you mean by the thermosensor?
Do you mean the low pressure switch? Or just the temp controller switch?

One more thing, setting the temp to high doesn't prevent icing up on low fan speeds.


Tiny
Essamshawky
Sep 24, 2012.
Not the switch. It is the sensor tht has its base plugged in between the cooling coil fins. That is teh temperature control sensor, usually called the thermostat.

How high did you set the temperature? If setting does not help, you might need to replace the thermosensor or check if it is bad and not sensing correctly.


KHLow2008
Sep 24, 2012.
Thank you very much, I referred to the service manual of the car which I normally use in such cases and found out that my AC system doesn't include such thermosensor
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Tiny
Essamshawky
Sep 24, 2012.
There must be a sensor to sense the temperature of the cooling air for temperature control.

In this vehicle I believe is called the inside air temperature sensor.


KHLow2008
Sep 24, 2012.
I will recheck and get back to you.
Thank you vey much


Tiny
Essamshawky
Sep 24, 2012.
It's not there sir, I am positive
the system depends on the low pressure transducer and tge high prissure switch attached to the compressor only. No thermistate at all
I can attach an image to prove that. But it seems that my AC system is not the one in ur mind

thank you


Tiny
Essamshawky
Sep 24, 2012.
Is your system manual or automatic HVAC?


KHLow2008
Sep 24, 2012.
Manual


Tiny
Essamshawky
Sep 24, 2012.
Ok, this system uses the heater for temperature controls and attached are the procedures for diagnostics.


KHLow2008
Sep 24, 2012.

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