A/C problem, the cause was the A/C Relay ...

[marginal]

Well, this has probably been already mentioned, but I feel obliged to write about it again as this is the first step one should take to troubleshoot an A/C problem with these symptoms:
Symptoms:
The A/C starts working and works OK for about 10 minutes, then, no more A/C ...
There's a clicking sound coming from behind the glove compartment where the A/C Relay is located.
First thing to do is check the relay as per the following procedure coming directly from the manufacturer:

In my case, that's what the problem was.
Some sellers on eBay sell those for $7 shipping included, some for $30, but it's still better than the $60 that Volvo charges.
Here is what's written on it: Hella 4RD 003 520-52 Volvo 9130270
Its pic:
The drawing from Volvo:
This relay is used in the following models: 93-97 850's, 98 V90, 98 S90.
Hope this will help someone !!!

[whoa]

These pinouts are incorrect! There should be continuity between 1 and 3 when voltage is between 2 and 4. This is a standard iso mini relay. The activating +12v goes to pin 85, ground to pin 86, which switches continuity between 30 and 87. The pins are marked on the relay.

http://www.accessconnect.com/car_relays.htm

You can open the relay, by the way. The contacts can get dirty; try cleaning them with paper & electrical contact cleaner.