I just brought a RX350 and on the display it says the a/c is on -- how do I turn it off?

 

Typical of Lexus as the Auto is on. Just leave it and adjust the temperature to your liking and the A/C although enabled (on) will only turn on when needed.

Also in dead of the winter, when you turn the defroster on, the AC needs to come on to pull the moisture out.

Salim

 

However, and to just to answer your question, you could go through the menu/display and switch off the bright green button for AC on screen.