Help, I need some help. My AC only works if I'm going fast, 50 mhp or more. I took the car to the mechanic and he changed a "relay" of some kind. he said he also reprogramed some software and changed the thermostat and he also said he changed a temperature sensor. None of this has fixed the problem. At the shop, when we test it, it would cool for about 2 minutes. (just enough for him to say: See? it's working just fine" ) but when I leave his shop, the damn thing starts blowing warm air. It's summer in So Cal and I need my AC. What should I do? Thanks in advance for your answers. My car is a Volvo S60 T5 with 180k miles.

 

Is the cooling fan running?
Also when it blows warm check for power at the compressor.