1991 camry a/c problem

The compressor engages and runs for approx. 5 seconds....light starts blinking on the "on/off button on dashboard and compressor cuts off. I've had freon level checked and was told it was fine. I replaced the relay and the on/off button on the dash. If I manually re engage the on/off button every 5 seconds, it cools nicely. Any suggestions will be greatly appreciated.