Based on a lot of advice I have received on the board, most recently from Jake, I swapped out the a/c relay behind the glove box in order to try to stop the tick-tock sound coming from that relay (which is signifying the compressor turning on and off). Those who have heard my saga know that, last time I had it checked, I am not experiencing that sound due to being low on refrigerant (the usual reason). So it's got to be something else, and my next stop is the a/c low pressure switch (a.k.a. the pressostat)

Jake, if you're out there (or anyone else who can answer), you told me that I can replace the pressostat without losing refrigerant. I just want to reconfirm this. Why won't I lose refrigerant when I tap into that line?

And just in case anyone is interested, I have signed up to receive access to all the Volvo 850 TSBs through Alldata.com. It cost me $24.95 a year and while there's not a wealth of information, there's a fair amount. At least now I have access to all the TSB detail and not just the titles. If anyone wants to get more info about that you can go to www.alldatadiy.com