On occasion, the AC on our '04 XC90 (249K miles) cuts out. It happens rarely and without obvious reason. For example, it worked fine on a 330 mile drive on Thursday, but it cut out on my way back from a 3-mile run to the grocery store today. Shutting the car off and restarting it does not fix the issue, though I wouldn't be surprised if it works fine tomorrow when I drive the car. Any thoughts?

When it’s in the non-working mode watch the compressor clutch when an assistant in the cabin calls for cold air. Does the clutch engage? At 249K the clutch may be worn to the point that it needs to be shimmed.

Thank you. At the risk of appearing dense, how would I know whether the clutch is engaging?

When your assistant clicks on the AC you should hear a "clack" sound and the inner part of the compressor pulley should start spinning along with the out part. Also the engine RPM's may dip momentarily due to the increased load. If the inner part remains stationary then the clutch didn't engage.

Got it. Thank you again! I now remember; I actually did this fix on our old V70 several years ago. I used the little plastic clips that come with loaves of bread. worked like a charm!