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AC only works when RECIRC button is pressed

tmarkwald

By tmarkwald
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tmarkwald New Member

tmarkwald

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2009 Avalanche 1500 - Kinda odd - the compressor never turns on when the 'fresh air' light is on., Pressing the recirc kicks on the compressor. Doesn't get really cold though. low side at about 45, high side at 195. Wondering if I have more than 1 issue. Lines get cold, seem fine. Lots of condensation - when sitting in humid conditions plenty of water coming off the lines. Plenty of air, just not ice cold, only when in recirc mode though. Wondering if maybe blend doors are partially open so not doing a full recirc. Driver and passenger side are both the same temp though. Any ideas?

Doug_Scott Senior Enthusiast

Doug_Scott

Posted
Posted

Use a thermometer to test air temps.  Hands are notoriously inaccurate.  If you are getting lots of condensation that will actually warm up the air coming out the vents.  A/C's job is to clean, cool and dry the air.  If it is really humid outside, you will not get real cold air.  If you want real cold air, you turn on the Recirculation option.  That will recirculate the air you have, and it will eventually make it cold inside the truck, and so dry your eyes will begin to burn.

The blend air door may be hanging up, you may be able to hear it close if you can get under the dash and change the mode.  I know my works, kind of, because on cold winter days the door will close as I cross an intersection about 5 minutes from my house.  For the longest time, I wondered what that "thunk" was in the right front of the truck that only happened as I crossed that intersection, and only when the temp was 0 degrees +/- 5 degrees C.  Couple of years ago I noticed it wasn't the suspension making the noise because it did it with the truck parked and me sitting in it, too lazy to scrape the windows and since using the windshield washers to melt the ice, then leave that layer of ice that will not scrape off, I was sitting waiting for the heat to start working I heard that same clunk.  On my truck it is the blend air door that is hanging up in the cold, but as soon as it begins to work, it gives off this nice loud thunk noise that says the heat is on the way.

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