Rx300 Warning Buzzer

[zeroallan]

I have a 2004 RX300. Whenever I turn on the AC, a warning buzzer sounds. The AC works fine, but the buzzer will not stop. It has been in to Lexus for a couple of hours. They say the pollen filter was loaded and they changed it (for no charge), but could not stop the buzzer. They say they had to go back to the technical manuals, but still could not find the cause, and I have had to book the vehicle in for more checks. Any ideas anyone?

My thought is that the warning system might have a short when the ac is switched on, and a systems reset might flush out the problem. Lexus Sidcup say they have not seen this particular problem before.