2004 Es330 A/c Control Noise

[Lexus4us]

I am experiencing an annoying clicking noise coming from the general area of the passenger side dashboard when the "Passenger Temp" control is adjusted to a temperature BELOW the cabin temperature. When I adjust the temperature to a setting ABOVE the cabin temperature, the noise stops. Could this be the THERMISTOR (Cooler, Room Temp, Sensor) or possibly a SERVO issue? Any help or advice is appreciated.

*Anyone know where the THERMISTOR is located on a 2004 ES 330?

[gbhrps]

I suspect that you'll find its a servo motor that opens and closes an air mixing door.

Whenever there are problems that have to do with the HVAC unit, there may be a minor fix (I'll get to that in a moment) that's easy because you can lay on the floor and get at the culprit, or you may be looking at major dollars because the dash has to come out of the car in order to get at that particular area of the HVAC unit. Every car is different.

Don't get your hopes up, but many issues can be corrected by doing a reset of the HVAC computer. Your problem may fall into this category. My 2003 GMC truck had no heat coming from the floor vents last year. Someone suggested doing a reset of the HVAC computer to correct it. I went online to a GMC/Chevrolet Forum and did a search for the problem. About 5 minutes of searching posts, I found a thread where someone had a similar issue as mine. A responder gave a link to the reset sequence, which I printed out, tried it the next day, and bingo! ... the floor vents started working again. The sequence was like "turn the key to ON, press the AC button and hold for 5 seconds, then press DEFROST". Nothing too complicated.

I'd do a search for the HVAC reset code online, and if that turns up negative, go ask a Lexus Tech what they think the solution is.

They may have the answer for you, or they may want you to part with some cash.

[LennyF]

I didn't know you could read cabin temp. I can read outside temp but how do I read cabin temp?