[s-cars] More A/C Questions

[Brian Powell]

The wife's 96 A4 A/C system is very similar to my S6's system, and
this last weekend her car started acting up. When the A/C is enabled
via the CC head, you can hear the relay in the driver's side footwell
click on and off for the compressor. When the compressor kicks in, the
car sort of stutters, enough that passengers ask what is happening. It
then repeats this cycle rapidly such that you are stuttering down the
street with the relay click/clacking the whole way. Cold air blows out
of the vents though, not as cold as it used to, but cold.

When the system was normal, you would never hear the relay, and if the
compressor kicked on or off, you never felt it in the cabin.

I dumped the CC codes, and the only ones present were 13.6 and 13.7
(relating to the footwell flap) which seems to have been a one-time
deal since changing the direction of flow on the CC head gives you
what you expect.

So, the question is what is causing this? Is it a sign of a weak, shot
relay? Is the system low on refridgerant, so the pressure switch is
kicking on/off? Is the compressor clutch going bad?

Any tips are appreciated.

-- 
Cheers,
Brian