A/C Woes

Discussion in 'General Chevy & GM Tech Questions' started by unctarheels01, Aug 7, 2009.

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  1. unctarheels01

    unctarheels01 New Member

    Good afternoon all,

    I have an 03 Tahoe with rear air and the auto climate control. My issue is this. The compressor only works intermittently. It has been replaced due to the slugging issue. However, I still have the compressor kicking on and off. On 110 degree days, that sucks. I can come up with two possible culprits. The pressure switch and the evaporator.

    The pressure switch or expansion valve due to the fact that it (by a seat of the pants feeling) does not keep a constant pressure, causing it to cycle on and off for varying periods. It could be 5 minutes, it could be 50 minutes. Based on my usderstanding, the system should operate at a constant pressure. If this switch goes bad, the system will build pressure and operate. When the pressure bleeds off, it will kick off to rebuild pressure.

    The evaporator due to the fact that while it cycles off, the climate control system increases air flow, but the air is moist. I live in the desert.

    What are your thoughts or experiences with this? Thank you in advance.
  2. gmagilla

    gmagilla New Member

    With moist air coming out could it be freezing up ? I had a big truck freeze up and it seems like they had change the expansion valve , but it seems like no air got through as it would freeze solid and the fan could'nt push the air through. Just a thought , good luck .
  3. azdrtdog

    azdrtdog New Member 100 Posts

    get some gauges it could be high pressure or low pressure if the expansion valve is malfunctioning it will trigger either safety to shut it down and the air will feel moist because its not dry and cold. stuck closed it will give high high side and the low low side causing high shut off. open and it will give low pressure on both with low side low pressure shut down
    Last edited: Aug 7, 2009
  4. unctarheels01

    unctarheels01 New Member

    Thank you for the suggestions. Still need to get the guages.

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