[V6-12v] V6-12v Digest, Vol 75, Issue 1

[Eric Sanborn]

The high side won't get cold.  It will actually get hot as compressing the
refrigerant makes it hot.  Once it goes through the condenser this extra
heat is dumped.  Once it runs through the throttling valve it expands and
absorbs a bunch of heat while running through the evaporator.  Since not
quite all the heat gets absorbed before it hits the compressor again the
cold inlet will be cold.

It can be hard to tell what is going on if you don't have high and low side
gauges.  They don't cost all that much so I would recommend getting a set if
you plan to do any work in the future.  It sounds like the A/C control is
not cycling the compressor as often since some parameters are not correct.
 It does this to protect the system.  It could be that your high side
pressure is spiking due to a blockage in the expansion valve and that is
cutting the system off (and killing performance).  If you don't to buy a set
try and borrow one.  Then it should be easy to diagnose.

Have you made sure there is nothing blocking the condenser and that the
electric fans (if equip I wasn't really paying attention to what year this
was) are cycling properly?  Have you measured what temperature you are
getting out of vents?  I have a wired indoor/outdoor thermometer that I
stick the outdoor temp probe in the center vent.  Knowing how the
temperature behaves can be helpful.  One of my cars freezes up after a while
and just stops working.  Without the thermometer it would have taken a while
to figure it out.

-Eric
www.sofadog.net/4ktq/

On Sat, Jul 17, 2010 at 12:46 PM, Austin Franklin <
austin.franklin at charter.net> wrote:

> Hi Jon,
>
> Thank you for your reply.
>
> I checked the compressor was fully on by setting the temp to "LO". I have
> the low side pressure switch removed to use an adapter on the connection to
> charge the system.  I have the two connections on the cable/connector
> jumpered with a paperclip.  If I remove the paperclip, the compressor
> clicks
> off.  If I install the paperclip, I hear the click, and the compressor
> turns
> on.  At least I am believing the compressor is turning on/off because of
> the
> loud click from the area where the compressor is.
>
> The low side pressure, according to the gauge on the can, is just slightly
> above the acceptable range, which is why I'm believing the system is fully
> charged.  I don't want to overcharge it.
>
> I can feel the high side line get cold, but not the low side line.
>
> I don't know enough more about this system to debug it though, and I guess
> I'll need to learn it.
>
> Any suggestions?
>
> Best Regards,
>
> Austin
>
> > -----Original Message-----
> > From: Jonathan [mailto:jhhummel at bigpond.com]
> > Sent: Friday, July 16, 2010 8:37 PM
> > To: v6-12v at audifans.com
> > Cc: austin.franklin at charter.net
> > Subject: Re: V6-12v Digest, Vol 75, Issue 1
> >
> >
> > Hi Austin,
> >
> > THere is meant to be a temperature difference between the outside
> > vents and
> > centre vents. I can't remember the exact reason for this, it is
> > either for
> > better temperature control or stuffiness in the car, OR it is to
> > prevent the
> > side windows fogging up. Eitherway, that part of your car is fine.
> >
> > I had similar issues, and that was because it needed recharging. The main
> > symptom was that the compressor turned off (relatively) quickly
> > but you said
> > that was good. How did you check by the way?
> >
> > In the centre console, there is a small vent looking thing in the
> > middle of
> > it, between the radio and temperature controls. That is acutallu
> > a vent. If
> > you rempve the cover, there should be a small rubber tube which
> > disapears into
> > the car for a bit. It terminates with a small fan and thermistor.
> > I've found
> > that tube tends to detach easily. Check the fan and the tube.
> >
> > cheers
> >
> > Jon
> >
> >
> > > Date: Fri, 16 Jul 2010 12:11:41 -0400
> > > From: "Austin Franklin" <austin.franklin at charter.net>
> > > Subject: [V6-12v] A4 air conditioning...
> > > To: <v6-12v at audifans.com>
> > > Message-ID: <HEEFIAEMADGNPEOKGDKNMEOMEOAA.austin.franklin at charter.net>
> > > Content-Type: text/plain;   charset="us-ascii"
> > >
> > > Hi,
> > >
> > > The AC in my 1996 A4 blows not so cold.  Interestingly enough,
> > it blows a
> > > bit cold in the middle two vents, but not cold at all on the
> > two side ones.
> > >
> > > I checked the A/C charge, and it seems to be good.  The compressor does
> > > cycle on/off, as I tested it with the pressure switch.
> > >
> > > Any thoughts?
> > >
> > > Best Regards,
> > >
> > > Austin
> > >
> > >
> > >
> > > ------------------------------
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> > >
> > >
> > > End of V6-12v Digest, Vol 75, Issue 1
> > > *************************************
> > >
> >
>
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