05 Rx330 Heater Problem

[330Lover]

I own a 05 Rx330 and the heater does not cool down after adjusting the temperature from 75 to 66 degrees. The heat that comes out at 66 degrees is so intense, I have to turn it off to be able to breathe, or open the windows.

[SW03ES]

How do you have the system set, on Auto?

[Lextech23]

You may want to take that to the dealer, there could be a problem with the ambient air temp sensor.

[330Lover]

Would the ambient air temp sensor cause the heat to keep pouring out until the car reached whatever temp was set? Or should the heat cool down when set to a lower temperture?

[330Lover]

How do you have the system set, on Auto?

←

No...I'm setting it manually when I first get into the car to 78 degrees until the car starts to warm up, and then reset it to about 70 when it warms up. But the heat still comes out blasting hot.

[SW03ES]

Thats why. I've found that on manual mode its very difficult to control the temperature of the air, next time try leaving it on Auto and setting the temp to 74 or so, it will heat up and back off when it gets to the proper temp.

When you select the temperature manually the heat will never back off, the interior temp sensor is deactivated and the unit works like a HVAC control system. When you turn the temp down the air doesn't get cooler, it just blows less hard.

[wwest]

An open IAT, interior air temperature, sensor will result in the HVAC ECU "thinking" its too damn cold in here, and always heating the cabin except at max cool, 65F.

Behind the little louvered window above the drivers right knee in my 01 RX300.