I have a 99 Catera and the A/C isn't working properly. It gets cool but not enough and it seems to get cooler when I bring up the RPM's. I Have evacuated and charged the system 3 times on a very good snap-on A/C machine. I put in the correct amount of refrigerant and there are no leaks. I noticed that whan I turn on the A/C the auxilary fans dont kick on like they are supposed to. Now when i rev up the engine the Auxilary fans kick on. I also noticed before the fans kick on the pressure in the system is very high and as soon as the fans kick on it drops to normal. I belive that because the fans are not kicking on that my A/C isn't going to work properly because the pressure is to high in the system, I'm only assuming if I'm wrong pls tell me. So my question in all of this is what is causing my Fans to not engage at the proper time, or does anybody have any suggestions on my problem. I forgot to mension when I'm on the highway the A/C works alot better. I get some cool air now but I know that somethong isn't right and I need it to be right. I welcome any and all suggestions. Sorry this is so long I just wanted to explain it in detail so not to confuse anyone. Thanks for your help