[V6-12v] ac refrigerant question

[Elliott Potter]

On Tue, 30 Mar 2004, Jack Tozzi at Novi Cantori wrote:

> Hello All,
>
> The AC in my 1995 Audi 90 is not delivering cool air this spring.  I haven't
> done any troubleshooting to speak of but I can say that the compressor is
> not engaging when I hit the AC switch. This makes me suspect the low
> pressure switch is being tripped.

Very often under a low pressure condition the compressor will cycle on
and off at least once when you turn it on, unless the pressure is
*really* low.  You don't happen to have the automatic climate control
(as opposed to the three knob system), do you?

> My dilemma is I'm not sure which refrigerant the car is using.  It was built
> in 06/94 but was in an front end accident prior to my purchasing the car in
> 2001.  Because of the accident, the condensor has been replaced and I can't
> find any other place where the refrigerant type is listed.  It seems very
> likely to me that the car has to have 134a because parts of the system was
> rebuilt because of the accident, but I'd obviously like to avoid
> contaminating the system by adding the wrong refrigerant.
>
> So, does anyone know for sure what the car originally came with?  Bentley
> was no help, it simply provided service info for both systems.

Audi changed to 134a in October 1992, so you're sure to have
R134a.  There should be a silver sticker on the back of the hood, on the
passenger's side that says so.

There's also no easily-accessible low-pressure port on the R134a
systems; charging is supposed to be done through the high-pressure port
on the front of the condenser.
--
Elliott