Pretty obvious - A/C compressor clutch is failing. Common problem with this gen.AC blows cold air when working but intermittently fails . When failed ac clutch is not engaged. Mechanic has evacuated all refrigerant and refilled to proper level. Has he kc clutch operation which seems normal.
When ac failed in my driveway one day, noticed when opening hood that neither the radiator nor condenser fan were operating. I happened to have my garden hose nearby and sprayed radiator from engine side. Fans started up and AC clutch engaged and AC delivered cold air .
AC has been working every trip to mechanic so unable to duplicate. Trip to dealer also fruitless - they managed to refill the already filled refrigerant.