Marine, the compressing action of the AC compressor is not electronically controlled as I understand it. The clutch is engaged and stays on when the AC is on, but the compressor internal control valve determines whether the compressor actually compresses refrigerant.

I know how you feel buddy, everytime the AC happens to cool I would say to myself, maybe it was this or that, but in my case eventually it reached the point it was not cooling more than it was cooling, and I replaced the compressor.

What you are experiencing now seems to be the "intermittent cooling" I went through, LOL!

I really do understand your hesitation as this is a problem/diagnosis that involves major work and an expensive part replacement to verify. I suggest that if your AC puts out cold air most of the time, just live with it in the meantime.

As I understand it, the valve is not a part that either works or doesnt; it can malfunction intermitently, or totally stop working. In my case, it stopped working often enough that I felt justified in taking the chance to replace the compressor assembly. AC was back to normal after that, which confirmed my diagnosis.

Lynhnn, I am not sure if your car has the same compressor as mine, my research indicates pre-facelift cars use Denso compressors as opposed to the Calsonic Kansei mine has. Labor should be about 3-4hours of work plus refrigerant costs at your favorite indy.