your use of the term volvo mechanic is my problem. it's what i do. i have to know what to do with any problem, ac or otherwise. i didn't mean to offend. if you notice, i don't chime in on ac questions too often because someone who doesn't know ac can screw it up or worse. that was the impression i got from your question. you have to have gauges and you have to know what to look for. the above post reminded me the volvo tool doesn't talk to the ac on your year, my bad. but, your guy, if he knows the cars, should also know, like i remembered after the above post, that volvo sells an adapter for the high side switch so the high pressure can be read. don't have the info handy, sorry.

again, apologies for the tone. if he's a pro, he should know. i do hope it works out. good luck, chuck.