Hello,
I have an 01 Civic. I was recently driving my civic in very hot weather and was constantly using my AC and it had been blowing very cold. I had been driving my car for over an hour and turned the car off for about 20 minutes. When I came back and restarted the car, the AC blew hot air. It was very sudden with no notice. I checked the fuse under the hood and all seemed fine, but it still blew very hot air.
I brought it to a mechanic who tested the system, he said the compressor was fine, and no coolant had leaks. All he could figure was that it was some sort of electrical relay problem, but could give me no sort of estimate until he "got it all apart". I was not comfortable with an open ended bill. Any idea as to what this may be, or steps I could take to repair it. Thanks so much for any help.

 

Check whether hood fuse 1 or dash fuse 14 is blown.

When you push the A/C button, does the button light illuminate, do the condenser and radiator fans run, does the compressor clutch engage?