how AC clutch cycles? AC thermostat checking?

[David]

Pressures are the key. Low side should be 30-35 PSI. But you say vent temps are too LOW at 50*F? I say that's too HIGH, my vent temps are at 38*F (but it does take a LONG time to get down that low, 55*F comes quickly)and I'm considering giving the temp sensor another crank to get it down to 35*F...

Dave
1987 CGT Special Build 2.3
SE Virginia

>
> From: Konstantin Bogach <kbogach at comcast.net>
> Date: 2003/07/01 Tue PM 08:09:40 EDT
> To: Peter Golledge <petergg at dimensional.com>
> CC: Eric <eric-audi.ql at mindspring.com>,  quattro at audifans.com
> Subject: Re: how AC clutch cycles? AC thermostat checking?
>
> Measured  vent temperature today - 50F.   It is too low but I saw clutch
> cycling.  What is most important to target - amount of refregirant or pressure?
>
> Konstanatin.
>
>
> Peter Golledge wrote:
>
> > Konstantin,
> >
> > >From my limited experience you should be OK with 30 PSI on the low side.
> > Did you have
> > the radiator shroud panel in place?   Without this in place the rad fan wont
> > do a good job
> > cooling the condensor which in turn means the evap wont cool real well.  I
> > would take the
> > car for a spin with a temp gauge in the vents.
> >
> > Cheers
> > --
> > Peter Golledge.
> >
> > 89 200TQA (R134A converted... cool)
> > 89 Saab 900i (R134A converted friggin freezing with no Cimate control)
> > 79 930 Porsche (R12 waiting on a conversion)
> > 87 LT1Q (No room for Aircon with the V8 motor in a 5K!)
> >
> > ----- Original Message -----
> > From: "Konstantin Bogach" <kbogach at comcast.net>
> > To: "Eric" <eric-audi.ql at mindspring.com>
> > Cc: <quattro at audifans.com>
> > Sent: Saturday, June 28, 2003 8:55 PM
> > Subject: Re: how AC clutch cycles? AC thermostat checking?
> >
> > > The only misbehaviour, as I suspected, was "no cycling" after 10 min of
> > > running.  When compressor is on low pressure is 30-32 psi, high pressure
> > is
> > > around 200psi.  The only numbers for low pressure I saw was great Peter's
> > > Golledge post about conversion procedure.  It states 30-35 psi is a norm.
> > I
> > > got there right after third can of R-134A.
> > >
> > > Konstantin.
> > >
> > > Eric wrote:
> > >
> > > > As far as how much charge weight of refrigerant is more important than
> > > > pressure.  Recommendations I have heard put the charge of R134a at
> > > > around 80% of an R12 charge by weight.
> > > >
> > > > I have never put my manifold on my Audi (still works great with R12) as
> > > > I don't want to mess with a good thing.  I have seen the numbers for my
> > > > Suburban when I converted it.  Its low side pressure cycles between
> > > > about 55-60 psi when off down to 25 psi when the compressor cycles off.
> > > >
> > > > Have you had guages on it when it misbehaves to see if something is
> > > > changing before it happens?
> > > >
> > > > -Eric
> > > >
> > > > Konstantin Bogach wrote:
> > > >
> > > > >Hi.
> > > > >I just finished AC conversion.  The leak I reported 2 days ago was
> > > > >probably due to not tight connection at manifold and not tight low side
> > > > >shreder valve.  I took 3 cans of R-134A with low side pressure at 30psi
> > > > >and refused to take more when I tried to  raise it to 35psi.
> > > > >
> > > > >Now the problem (may be not):  after 10 min working at 90F outside
> > > > >clutch does not cycle.  Does it look normal?
> > > > >
> > > > >I removed thermostat, hooked up DMM  and it shows 1.3 Ohm.  Shouldn't
> > it
> > > > >be short (0 Ohm)?
> > > > >
> > > > >Thanks.
> > > > >Konstantin.
> > > > >200tqa '89  (now with cool air!!!)
> > > > >200tq '89  (will have cool air soon)
> > > > >S4 '93  (did not nose anywhere yet, and air is cool.  Wierd!)
> > > > >
> > > > >
> > > > >
> > > > >
> > >
>
>