A/C blows cool for a while then blows slightly cool or at outside air temperature. Eventually it will go back to blowing cool again. I took it to a mechanic that said it was the A/C compressor relay. He was not able to find that Infiniti part without buying the whole $800 module. He did find one from a Nissan that he said looked identical and installed it. The problem seemed to go away for about a week and is now back. Does this part actually sound like the problem? If so, should I try to find one used? If not, what other suggestions do you have.
If it is a relay, there shouldn't be any problem getting a replacement part as these are generic in nature. If it is the controls, that would be a different matter. Without any proper diagnostics, it is not possible to determine if the diagnosis was correct or not.