My daughter has had her Prius V for a couple year, purchased used. Last year there was a leak in the condenser up front and that was replaced and the system recharged. It worked fine until recently where of course now it's not cooling. I fired up Techstream and in Active Test mode I can ramp up the compressor speed to 7500 RPMs (as shown) but it doesn't make much if any different in the air temp. I can see liquid in the sight glass and the pressure sensor in Techstream shows about 150-155psi so it's not empty, though I'm not sure what that sensor reads normally. If the engine is on battery when parked and I turn the A/C on high the engine typicaly kicks on and it sounds like the compressor is buzzing, but again I'm not sure what's entirely normal on these vehicles since I know the compress operates differently. My next step is to spend $160 to have someone diagnose it, but I'm hoping from the description there's something obvious.
You could check the cabin filter and verify its not clogged or being used as a nest. Odds are its low on refrigerant based on the compressor is working (it stops with excessively low pressure) and the fact its cooling to 80f with 102f ambient. Low refrigerant means there is a leak. The sight glass with a leak will show bubbles/ white foam occasionally or all the time depending how low it is. A manifold gauge and subcool calc is a better indicator of low refrigerant. If we want to speculate on something more costly, the air blend door could be bad allowing the heater core to add heat. Normally you can hear and feel the difference in air flow by switching between air flow modes. Increasing the heat to max while air flow mode is through the dash vents should result in increased air flow and a different air flow sound. Partial foamy bubbles
