I have an 08 S40 and the AC works great for a little while, but after it runs for a bit it cuts off. I do residential AC and have checked the system for leaks and have vacuumed and recharged the system but still has the same issue. Seems to shut off on a high head pressure. It's been in the shop twice and the first time they said nothing was wrong. Second time they said it might be the high pressure switch. I've had the gauges on while running and the pressure rises when the RPMs start rising and that's when it shuts down. Seems to me the high pressure switch is doing exactly as intended. Pressure gets up over 400/450 PSI. My question is does anyone else think it is the switch or could it be something else causing this problem? We live in Florida and it is way too hot to be driving around with no AC. Please help!
