Toyota Repair: ac light blinking, freon, camry

Question
I have a 1987 Camry wagon. A few days ago the a/c light started blinking and stopped blowing cold air. Now when I first start driving it'll usually work for a few minutes and then start acting up again. What could this be?

Answer
There used to be a common problem with the a/c compressor revolution sensor, if the system has enough freon and the compressor and the clutch are good then I would recommend replacing the revolution sensor, keep in mind that the sensor is under freon pressure and the system has to be evacuated before doing anything.