katie10543

Wow, that's quite sophisticated, I guess you do learn something new every day! Thanks again! -Katie (Sorry I posted this in the wrong spot. I'd move it, but I don't see how that can be done.)

Thanks for that good description and the suggestions on how to avoid the noise. Indeed the noise I hear is the servo moving the door back and forth -- often as fast as once a second. I had discovered the fact the MAX COOL will lock the door to one side, but I'm not sure that I can attain good temperature control by just using the fan speed setting when it's in that mode -- I'll try it. I'm surprised that the mileage would improve in MAX COOL mode as the AC compressor would be on all the time, right?

I've got an 99 RX300 with 167K miles on it and running great! The only issue I have is a longstanding one that's been getting worse over time. The blend door (so I'm told by a Lexus mechanic) oscillates back and forth rapidly when the outside temperature is high. It's gotten to be quite noisy recently and I'm wondering if there's an easy way (i.e. something that I can do myself -- I'm pretty good at minor car repairs) to quiet this down. The AC and heat work fine as does the blower fan, temperature regulation and all vents and valves to those vents. Thanks, Katie