The good news is that when I start the engine after it has set overnight and is completely cool, my A/C blows cold air. And will continue to blow cold air for hours as long as the engine is left running and A/C is left turned on. But after engine has run long enough to be at normal temperature, and then the engine is shut off and restarted, the air blown fron vents is no longer cold. Also, I discovered that the when this happens, the A/C clutch doesn't engage when engine is restarted.

So...I'm guessing there is a bad relay, sensor, fuse or switch that gets hot and won't send the "on" signal to engage the A/C clutch. Any suggestions or guidance would be appreciated. If you know, please include location for any thing I need to check or replace.

FYI, new A/C compressor was installed about 5 years ago. A/C was converted to R134 years before that.