Infiniti G35X air conditioning poops out when I need it most

Help! Infiniti air conditioning stops providing cool air when its hot (over 85) and i’m sitting it traffic. Dealer(s) have tested AC system and said pressure is fine and system isn’t leaking. Temp gauge never shows a sign of overheating and blower keeps blowing - just really HOT air - like politicians. Can anyone help?

Several dealers cannot fix it. Time to try next shop. You have car. You can go to shop. We cannot fix your car. Is compressor running AND you have warm air at vent? Pressures are good so we can assume so. I cannot assume so cuz I will get chastised here.

If you have automatic A/C, which does all the thinking for you, you may have a faulty air door control. That should be checked out first. If the compressor is OK and the refrigerant up to the right level, it SHOULD cool.

I would go to a specialty A/C shop; they do this all the time, and their rates are reasonable compared to dealers.

Maybe help the next shop by looking under the hood and looking at the compressor. When it cools properly, the piece on that’s on top of the pulley of the AC compressor will spin as fast as the pulley (that’s called the AC clutch). When it doesn’t cool, see if that piece still spins.
Start there. It may help whomever will fix your car.

I don’t know much about it but as the others have said you can help isolate the problem by checking to see if the compressor is running or not when its blowing warm air. Next would be to check if the air door is changing positions that shuts the air off and turns the heat on. You might be able to hear the door close or turn the defrost on and see if you get cold air through the vents. If the compressor is off, then you could have a problem with the pressure switch that thinks the pressure is too low. If the compressor is on, you could have a worn compressor or problem with the air door motor (vacuum source) or air door itself. Sounds like maybe you need to go to an actual auto HVAC shop instead of the dealer though if it is not under warranty.