Why does the A/C Button ALWAYS come on when I use the Auto setting for the climate control in my 2000 RX? I mean I have it cranked up to 90 degrees and the freaking A/C light is on. Why would Lexus do this? Put more stress on the A/C components, reduce my gas milage, force more recharges of r134a. ???

 

Do you mean you can't turn the AC off, or the sequence of the function itself bothers? The AC is set to be on whenever you press the AUTO button, no matter what temp you set it at. After pressing the AUTO, you can then press the AC button and the AC will be off while the auto climate control is still on.

The AC and AUTO shouldn't restart everytime you shut the engine and restart. Once you've pressed AUTO and AC, the climate control will be on each time you start up. So, if it's winter and you're always having it set at HOT, then just leave it alone. You can still adjust the temp without affecting the AUTO.

 

The automatic climate control will use the A/C as much as possible. Even if it's not being used for temperature, the system will use it as a dehumidifier. It will do that as long as the temperature outside is above freezing.

Yes, that probably does put more drag on the engine and gas mileage. However, I think there might be some benefit to running the A/C a lot more often - it keeps the hoses, seals, etc., used to operating regularly and properly lubricated inside. As a result, you don't have a sudden problem with the A/C not working on a warm day after it's been turned off for 5 months.