I got my 850 in october, knowing the Ac wasn't working/leaking. I have an invoice from the previous owner that says his mechanic (Some Sullivan Tire place in NH, not a Volvo guy to my knowledge) found a low pressure int. switch problem, and that a recharge was done. That was about a year ago. A couple months ago my mechanic, an ind. Volvo guy in RI said my system was low. So today i put in a can of R134a, and I had A/C. I also noticed green dye had been put in. Before doing this i had just hot air. When putting the can into the system i had to attach a jumper wire to get the compressor to cycle, so it must have been low. I told my mechanic a month ago about the supposed switch problem and he told me that the Sullivan guy might be wrong, that his guess is the Evaporator. So what I'm asking is do you guys think the Sullivan guy was right? I mean he did use a dye, so most likely he saw where the problem was, no? Should I just tell my mechanic to just go ahead and fix as the invoice said, or should I have him do his own check? I don't want to pay for a diagnosis if I don't have to. Thanks for your help...