You need to check the high side pressure too. But unless it's in the 50's to 60's when your pressure shouldn't be that low. you should be at least 45 and on Max AC (Fan on high set to recirculate) and the car interior hot it should be in the 45/240 range as the interior cools or if you try it at night when it is cooler, you may see the high side pressure drop to about 150, most GM cars since the late 90's use a variable displacement compressor pump so there is no need for cycling. I am not sure which ones have it and which don't, but the one in my 05 GTP is and so was the one in my 97 PA. Not real sure on 00 GP but another one I looked at did use the variable displacement pump I just don't remember the year. Usually what happens with these (if they don't fail in the normal modes) is that the valve gets stuck on low displacement and while you are cruising down the road it's fine, but sitting in traffic it will start getting hot in the car.
Jeff
