[s-cars] AC compressor shuts off at 42 degrees F

[Tom Rodriguez]

Thanks Stott. I will check on the recirc door/flap.  

I should also mention that the window fogging occurs as soon as the AC indicator light turns off (i.e. the little snowflake on the HVAC control panel on the dash), indicating that the AC compressor is no longer engaged.  If the compressor (and the indicator light) come back on, the windows clear up immediately.

Case in point - on Tuesday evening this week I drove for two hours in the rain.  During the drive the ambient outdoor temperature fluctuated between 39 and 43 degrees F.  Above 42 degrees F the AC compressor was on and the windows were clear.  Below 42 degrees F the AC compressor was off, the windows were foggy, and the air coming through the vents on the dash was noticeably more humid.  This fluctuated back and forth at least three times during the drive.

Based on this description, do you think the culprit is the recirc door/flap?  Might there be another cause?

Tom Rodriguez
'95 S6, 281K miles

-----Original Message-----
From: Stott Hare [mailto:stott at gwi.net] 
Sent: Thursday, November 9, 2017 1:33 PM
To: 'Tom Rodriguez' <trodri69 at gmail.com>; s-car-list at audifans.com
Subject: RE: [s-cars] AC compressor shuts off at 42 degrees F

Temp range sounds accurate, don't recall if it was 42 or 38 or something else, but know the compressor will no longer come on below a certain ambient.

What I would check is the return spring connected to the center of the recirc door/flap.  When that spring is missing, the flap door isn't returned to the proper position and fogging ensues.  Replacing it in my old 200 or S6A cured it for me.

-Stott

-----Original Message-----
From: S-CAR-List [mailto:s-car-list-bounces at audifans.com] On Behalf Of Tom Rodriguez
Sent: Thursday, November 9, 2017 12:31 PM
To: s-car-list at audifans.com
Subject: [s-cars] AC compressor shuts off at 42 degrees F

The AC compressor on my S6 shuts off at ambient air temperatures below 42 degrees F.  This causes the windows to fog up, particularly if it's raining out.  Cranking up the heat on the defroster only makes it worse since the hot air is humid and the windows are cold.

 

Any DIY suggestions to fix this?  And what is the minimum temperature supposed to be for the AC compressor to remain engaged?  I'm going to ask the Audi shop to fix this if I can't do it myself, but looking to save some $$.

 

Tom Rodriguez

'95 S6, 281K miles

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