[V8] AC Failure

Fri Jun 25 11:07:36 EDT 2004

OK, we are getting closer!  Turns out the clutch is OK, the climate
control system just doesn't want to give it +12v (verified this by
energizing the clutch with t piece of wire connected to the 12V jumper
cable connector under the hood and also with a volt meter at the signal
side of the connector).

I found some good info in the manual for '09:
"Coolant temperature sensor G62, checking - Note: This coolant
temperature sensor is not installed on all vehicles (will be phased in
gradually).  On vehicles without coolant temperature sensor diagnosis
display on channel 6: 255=open circuit.  If no coolant temperature
sensor is installed or if the sensor is providing incorrect values, the
coolant temperature is computed by the A/C control head.  (The coolant
temperature is an input signal required for automatic control of the
blower speed.)"

I take it my June of '90 car doesn't have this sensor and that's why I
am getting error '09.

And now for error '16 - This high pressure sensor is located on the A/C
radiator, driver's side.  There is a red plastic connector located here
that sits vertically.  I disconnected it and it looked pretty funky
inside of the connector.  I started the AC with it unplugged and still
got the '16 error.  I then jumped it with a paperclip and no error, the
clutch engaged too.  I tried cleaning the contacts with some (cheap)
enhancer I bought at the Depot last night (couldn't find my good stuff).
I tried it this morning and was still getting error code '16. 

The manual suggests replacing the O ring and tells me not to worry, that
there is a Schrader valve to keep the expensive R12 in the system...  I
guess after being compressed for 14 years, the Schrader didn't want to
fully close the valve because it was hissing at me...  I quickly put
this High Pressure Sensor back in place (not sure how much refrigerant
came out).

What do you think?  Next step, take it to the mechanic to evac the
system, replace the Schrader valve and install a new O ring?  Or perhaps
drive around with a paper clip stuffed in the connector?  ;-)

Thanks for listening,

- Jeremy

-----Original Message-----
From: v8-bounces at audifans.com [mailto:v8-bounces at audifans.com] On Behalf
Of Jeremy Ward
Sent: Thursday, June 24, 2004 2:06 PM
To: v8 at audifans.com
Subject: RE: [V8] AC Failure

Turns out the relay wasn't the fix.  (Which is good because it is an
expensive part!)  The culprit seems to be the clutch on the AC
compressor; it tries to engage, but starts slipping.  I cut my losses @
$165 and still need to order a clutch and install it myself.

Any BTDT experience with replacing this puppy?  I am assuming that I can
leave the compressor in place and just R&R the clutch, right?

I am curious as to why I am still getting these codes:
'09 - Coolant temp sensor G62 open circuit
'16 - High pressure sensor - short circuit

Thanks in advance,

- Jeremy

-----Original Message-----
From: v8-bounces+jward=mti-interactive.com at audifans.com
[mailto:v8-bounces+jward=mti-interactive.com at audifans.com] On Behalf Of
Jeremy Ward
Sent: Thursday, June 24, 2004 9:20 AM
To: Scott Baumann / Progressive Technology Solutions; v8 at audifans.com
Subject: RE: [V8] AC Failure

Funny you should mention AC...  Mine has been down for a while and I
took it into the shop yesterday for a recharge; mine seemed to be
trying, but just couldn't do it.

They ended up replacing 'the filter' (?) and said it was full of metal
shavings.  Said it didn't take much R12, but they are waiting on a new
AC clutch relay to arrive this morning (I am currently sitting at a $300
bill...)

You might check out Chris Miller's site:
http://members.aol.com/c1j1miller/climate.html 

You can pull codes from the climate control unit ('90-'91 only) to see
if there are any errors.  Hold down the Outside Temp and the Off button.
Mine was scrolling between 09 and 16 and the relay was clicking on and
off.  Lets hope the new relay fixes it and my bill stays at $300.

Hope the link helps,

- Jeremy

-----Original Message-----
From: v8-bounces at audifans.com [mailto:v8-bounces at audifans.com] On Behalf
Of Scott Baumann / Progressive Technology Solutions
Sent: Thursday, June 24, 2004 8:58 AM
To: v8 at audifans.com
Subject: [V8] AC Failure

Hello to all.  After some 80K miles of hard travel in the past 1.5 years
with the old V8, she finally has come up with a failure (beyond normal
maintenance, that is!) that needs to be addressed.  I parked her in her
stall for the night (run hard & put away wet?) with a fully functional
AC system, as cold as I could ever ask it to be.  
    The next morning, my wife took a trip into the Twin Cities and back
- pretty warm out - about 85 Deg F or so - and she came home & remarked
that the AC was not working.  Strange.  Took her out for a spin to see
for myself.  Sure enough - the compressor is not willing to kick in.
The downside on this system is that, when the kompressor is kaput, there
is no real fresh air source to the cabin that does not see a temp rise
from theh engine/climate control system.  Makes for a warm drive!
    I have done some limited research in the archives (all 6 months
worth), without much success.  One thing I will try is to splice the
relay conn's to see if the compressor kicks on (I believe that bypasses
the high/low press and high temp cutout switches).  If the compressor
does indeed kick into service, I suspect that means that either I have
experienced a bizarre leakage of R12, or one of the various switches is
shot.
    Any BTDT's on trouble-shooting the V8 AC systems??

Thanks

Scott Baumann

_______________________________________________
Audifans V8 mailing list
Send posts to: mailto:V8 at audifans.com
Manage your list connection: http://www.audifans.com/mailman/listinfo/v8
Have an Audi V8 question?  Check the Audifans Knowledgebase!
http://www.audi-quattro.org/cgi-bin/twiki/view/Audi/V8
Have a V8 answer? ... Please help others by adding to the KB ... all
contributions welcome!