I have a 98 GTP with dual control A/C. Sometimes the a/c works and sometimes it does not. I was told at the dealership it was the unit. I am on my 3rd unit and the same thing continues to happen. One time in car a/c will work and freeze you out, next time in car it won't work. Fan is running but the 'on' button does not come on for compressor. I can push it and you can tell the a/c is trying to come on. Switch car off and get back in just few minutes later crank up and it will work fine. I am figuring it is not the unit at all. Was told compressor is fine. By the way...I live in Florida and it is 110 in the shade. Any suggestions quick I am melting???

Did you happen to rule out the clutch on the compressor? Put the a/c on, look under the hood at the compressor, Is the whole front of the compressor pulley turning, and not just the pulley?