Could also be as simple as a pipe or hose, that's all it was last year with
our 960 (we thought it was the expensive evaporator as well)... cost with a
mere (for an A/C fix $350 with labour and parts and diagnostic)... Now that
part only held for last summer and now something else is leaking - but
that's what you get for a 12 year old car....

To the original poster... A/Cs don't just get low on refrigerant...
something has to leak it out, they are a sealed system. Fixing your problem
could be as cheap as around $100-150 to get a leak stopping agent and a
refill (get the UV dye put in to see where it's leaking - you'll have to
re-visit the dealer/mechanic after 2 weeks for them to check it) or much
much more money.... We've put in around $800 into our 960's A/C system over
the years - it's easy to see why many 10 year old cars don't have a working
A/C anymore, we're keeping ours going because driving with the windows down
is hell when you're on the highway and our Volvo is our long distance trip
car - A/C is definately needed.

Hi John

It turned out to be a lack of gas and blocked pollen filter. All sorted for
£90!!  Phew!!

thanks for the info tho

Jim