[s-cars] AC Troubleshooting Help needed

[Jack Gagnon]

Hello all,

I need some help here.  I've got a 92 S4 and the AC is not cooling.  It has
been this way for about 1.5 years now.  With all this hot weather lately and
global warming coming, I need it fixed now!

Last time I had it diagnosed, there were no leaks and was told it needed a
re-charge.  Last week I got the system evacuated and refilled and still no
dice.  The compressor cycles on and off bit the evaporator never seems to
get cold.

I checked out hvac diagnostic channel 1 and got a bunch of codes
(7.3,8.3,8.7,11.7,15.1,18.3,22.3). I don't know how long they have been
there and are probably some are a result of the AC man tripping the low
pressure switch to put the refrigerant (R-12) into the system.  He filled
the system through the low side by removing the low pressure switch and
connecting his tank right to the exposed fitting and then shrting out the
low pressure switch with a piece of wire.

I put the system on low and monitored channel 52 and the compressor comes on
for 5 seconds and is off for about 20 seconds. the cycel repeast like
clockwork. I can hear something change in the air flow when the compressor
kicks in, but the no cool air and the air flow sound resumes to the normal
sound when it is off.

I think I need to clear the codes (anybody know how?) and run the
diagnostics again.

Here are the desciptions of the trouble codes listed above:

07.3 Ambient Temperature Sensor at Fresh Air Blower (G109), sporadic open

08.3 Temperature Regulator Flap Motor Position Sensor (G92), sporadic open

08.1 - 08.4: Temperature regulator flap motor will no longer be controlled
automatically; manual adjustment only.

08.7 Temperature Regulator Flap, sporadic block

08.5 - 08.7: Motor is cycled; software attempts to eliminate block. Watch
Diagnostic Channel 8 to see digital value for flap motor position sensor
(G92).

11.7 Central Flap, sporadic block

11.5 - 11.7 Motor is cycled; software attempts to eliminate block. Watch
Diagnostic Channel 11 to see digital value for central flap motor position
sensor (G112).

15.1 Back Pressure Flap Motor Position sensor (G113), static open

15.1 - 15.4 Digital value internally programmed for limp-home mode

18.3 Fresh Air Blower voltage, sporadic

22.3 A/C Refrigerant High Pressure Switch (F118), sporadic open

Do I have a blocked oriface?

Can anyone give me some advice here?

Thanks

Jack