Why is my AC light flashing

@dennispere33833 The reason why the A/C light flashes is because the A/C controller or amplifier is sending the signal to the A/C compressor to engage. There is a speed sensor located in the compressor which reports the RPM of the compressor shaft. If the AC amplifier does not see this signal and match it with the engine RPM then it shuts the system down and flashes the light in the A/C switch. There are a whole bunch of reasons that could cause this. Something like a loose or slipping belt, or the compressor clutch not responding, a failed pressure sensor or that the refrigerant has leaked out. There's also an A/C amplifier and the control panel that could be at fault. Even a bad AC relay can cause this. I'd start off by checking the relay and the wiring. Then check the refrigerant with a pressure gauge to check if your system has sufficient refrigerant.

It might also be a good idea to scan your OBDII and see if it reveals some error codes. Use this 2001 Toyota Sienna AC to help you with some of this.