About halfway through a 1 hour trip in 98°F sunny weather on the highway, my AC started blowing hot air (around 100-110°F). After this first incident, I can hardly get 10 minutes on the highway before it stops working again, though if I run the system in park after letting it cool overnight it'll run for an hour or more without issue. I checked fuses and relays and they appeared fine, though I noticed the condenser fan turned off at one point during one of my tests. The fan motor wasnt hot to the touch so I dont think it was tripping a thermal safety. I connected some gauges and got 17L/190H with the engine at 1500 rpm. I went over the all the fittings and vents with a leak detector and wasnt able to find anything, though I didnt thoroughly check the rear evaporator. I replaced the timing belt a few months ago so I'm hoping I didnt break a seal around one of the compressor fittings just by moving it to the side. I'm assuming its a leak, the pressures are too low according to the FSM. Either the leak is so subtle that my detector wasnt able to pick it up, or I wasnt checking the right places, any ideas?

 

Sounds like it's low on freon and computer turns off compressor as a safety precaution. You can try to top off the system with one of those AC in the can refills. Then see if it will work better/properly. Moving AC compresdor to the side when working on engine is appropriate method. I've done it multiple times when cganging timing belt and when I pulled the engine.