AC Pushbutton/Light Blinking

'96 Toyota Avalon. AC pushbutton/light blinks every so often. When this happens I can tell the AC isn't quite working up to par. When I turn it off, then on again, it stops bliking and works fine. Very intermittent.

Is this a typical indicator that the refrigerant is low/bad or might it be something else like the switch or something electrical?

Thanks.

Toyota's have a strange A/C systems. Unlike most other A/C systems there is a device called an A/C amplifier on the toyota's which gets an input from the ECM for engine RPM and an input from a revolution sensor on the A/C compressor. It compares the engine speed to the speed of the A/C compressor. If it detects that they are not in sync with eachother, it shuts down the compressor to prevent damage and flashes the A/C button light to let you know. does it happen after you drive through a puddle of water? If so the belt is just slipping because it is wet. If not, i would check the tension on the belt. If that is not the problem, the revolution sensor in the compressor is likely going bad. It's a common problem on toyotas. good luck