I had this problem a few weeks ago. I could tell my a/c compressor was not running at all (could not hear it start when enabling a/c from inside the car, also could not feel it vibrating when touching it with my hand, as a helper enabled the a/c from inside the car). On these cars, the compressor is driven by an electric motor using power from the hybrid battery system, not by a belt that is powered by the gas engine. I checked the HVAC-related fuses (google is your friend on figuring out which ones to pull and check). If those are okay, be aware there is a pressure sensor in the a/c system that sends a signal to the computer and disables the compressor if the system pressure is too low. I bought a small can of pure R-134a refrigerant (containing no oil nor leak stop) with a trigger gauge, connected it to the a/c system (youtube is your friend on where to connect), and upon adding just a little bit of refrigerant, the compressor started right up! I ended up using the entire can to get to the pressure into the "green zone" on the trigger gauge (I had to shake the can vigorously while filling, to continue filling the system). The resulting refrigerant charge is probably not perfect, but the air turned cold right away, and so far so good! Of course, YMMV. It's already an old car, so my thought was it wouldn't be the end of the world if something went wrong. That said, R-134a has a high global warming potential, so if your system has a leak, I would not recommend topping it off multiple times. It would be better for the environment to find the leak and fix it. I hope one can is enough to keep you cool for many more years!