AC suddenly not working

My 1996 Subara Impreza and I just returned from Cape May, NJ, where the AC was working fine.
This afternoon I turn the car on and the vents are blowing really hot air, even thought the temp dial is all the way to cold. When I select AC , just HOT air comes out. And, really, the air is hot! I checked the fuses, all ok. Any ideas?
180,000 miles, 1996.

After 16 years and 180,000 miles, this is bound to happen. The only ideas I can offer are:

  1. Chances are, you will need a new compressor. It could be something else, but the odds are against that. If you’re lucky, you might just have something simple like a leaking Schrader valve, but even that $1.50 part will cost you $250 to get replaced if it is the problem.

  2. There is no simple way to diagnose and fix an air conditioning system, so you’re going to need to take this to a shop if you want it to be fixed. You need to put this in the hands of a certified air conditioning technician, and you should be ready to spend between $900 and $1,400 to get the air blowing cold again.

Before you take out a second mortgage, go to the car, open the hood and see if you can recognize the air conditioning compressor. If you can, great. Then look at it carefully, go in the car and start it, and go out again. If the AC is off the belt should be moving the compressor pulley, but you should be able to see that the inside of the pulley is not turning. That’s because there is a clutch in there, and it’s off. Now turn on the AC and the fan, and look at the compressor. The pulley and the inside stuff should be turning. If it is not, you have an electric problem. If it is, then its a problem either that the compressor has no refrigerant or there’s a problem with the complicated things that direct intake air through the heater core or the AC cooler.

The cheap solution is to open the window and look forward to Fall, of course.