A/C Woes

[Sandy Duffy <sandyduffy@home.com>]

Hello all:

I'm back after a 4 week hiatus with a back-to-back vacation & business
trip.  New A/C problem in my '87 5KTQ has raised its head.  Most of the
time the A/C works flawlessly however on hot days when the car is fully
warmed up, it will cease to function (Of course this is when you need it
the most....Audi gods are like that...yeah; they are) until the day (or
car) has cooled down.  Then it will work perfectly until things get too hot
again.  Charge is full, blower works perfectly (its relatively new),
compressor is about 2 years old, A/C clutch is same age as compressor.
When the thing is misbehaving, the clutch will not engage (hence no A/C).
Any words of wisdom or BTDTs??

Thanks in advance

Sandy