I have an 05 Impala with the 3.4L. The A/C is not blowing cold. I have checked all the relays and fuses and all are good. This system is different from others I have worked on b/c it does not have a low pressure switch or clutch cycling switch so I have no way of cycling the compressor that I know of. I bought some freon from the parts store with a gauge and when I hooked it up it went in to the "Red Danger" area at about 90psi. I am sure that I am on the low side. So my question is will too much freon cause the compressor not to cycle or is there a clog in the system. There is not an orifice tube like in other R134a systems. Any help would be appreciated.