Hi Scotty, I bought a used 2004 Toyota Sienna. The AC was not working on it. So far I have changed the compressor, but the pressure release valve seems to go off every now and then. Also the AC some time blows cold air and then normal air. Any idea to where I should start to diagnose the issue.

first, I would change the expansion valve and make sure the ac fans on the radiator are blowing full blast

Thank you for the quick response. I did watch your video on how to replace expansion valve. Since the pressure release valve seems to go off, should I just wait till all the refrigerant is out or is it best that I go to a shot and have refrigerant removed.