Hello I have a 2003 Chevy Tahoe with the 5.3. Lately I have been having problems with the A/C. I will turn it on to the lowest temp on the dial. It will start blowing out cold air. But then a couple of minutes later it will start blowing warm/hot air out. I changed the a/c switch next to the accumulator and I just changed the a/c refrigerant pressure sensor that is on the A/C line going to the A/C Compressor. It is till doing the same thing. Could it be another sensor or a bad cable somewhere? Please help. Thank you.