redrocks

During the winter months, does anyone experience problems on having cool air coming out the dash vents. I usually set the temperature at 68 degrees using Auto and manually turn off the AC. From a cold start, engine warms up and heater activates, bringing warm air into the cabin (through the floor). after about 10 minutes, cool air will come out the dash vents. If I raise the temperature, cabin will heat up through floor vents, but then cool air comes through the dash vent after 10-15 minutes. The exterior temperature is usually between 30 to 50 degrees. So it's obviously not hot enough for need to "cool" the cabin.


A three hour trip one weekend, I had the thermostat at 76 degrees to keep the "cool" air from coming out?

Is this normal, I've had my 05 RX for about 3 months now.

Thanks.

triplecore

AC or REC can be turned off from AUTO via Lexus Personlized Settings. If your in auto and just change the direction wit pushing the fan speed it will stay in auto even though the green light goes out. I don't think it should be blowing cold air from the top and warm at the bottom it should be uniform.

Did you buy it CPO? If not have a dealer do a full car inspection.

biff44

I agree. That thermostat drives me nutz! I would rather there was just a lever with hot on one side and cold on the other, and I could move it around till I liked the temperature coming out of the vents.

I find the temperature coming out of the vents, in the winter, to be way too hot for me. I often drive around with the thing set a 65 or 66 just to get it to a reasonable temperature.

dave2K

I've had the same problem. When on Auto the system does not like to rest, so as soon as the temp goes above the target, it switches to cool air. This is especially common on a sunny cool day when the temp warms up quickly in the upper half of the vehicle while my feet are still cold. My solution is use auto to get to the temp I want and then take over manually. I think the system is working as intended, it just switches from heating to cooling at times when it should be taking a break.

redrocks

I bought it as a CPO so it's under warranty. I was trying to determine if this was normal or not. I plan on putting a thermometer in the car to see what the temperature changes are like compared to the Auto setting.

redrocks

Does anyone know the location(s) of the temperature sensor(s) that monitor the climate control? I found no information on this is the manual. My wife's Honda has two sensors to regulate temperature. Where are they located in the RX?

Thanks.

Lexmex

I am not sure on the newer RX. One of my neighbors has an RX330 but don't see her outside, but in the case of my RX300 right here on the front lower side.

redrocks

Where would the temperature sensors on the inside of the vehicle be located to monitor the use of AC or heat?

Thanks.

triplecore

I could not find its location, but I found part information for it at Park Place Lexus Parts

Ambient temp sensor, rx350
2007 $16.31 $13.86
In-car sensor, rx350
2007 $12.02 $10.22

Does not seem to much so if you have a problem with them I guess they can be replaced without a dent in your wallet

Lexmex

Room temperature sensor in my RX300 would be (if you were in the driver's seat) right in front of where your right knee would be and behind the panel there. There's a hose that hooks into it along with a small connector with a wire coming out of it.

redrocks

Thanks Lexmex, I found it last night. As I said before, my wife's Honda has automatic climate control as well. The Honda manual shows where the sensor in located and happens to be located in the same area in the Lexus. In fact, I would not be surprised if Honda and Lexus use part distributor.

Anyway, thank you for checking. I suspect the sensor may be the problem. I may move the small thermometer that I placed the the RX closer to the sensor to see if there are any discrepancies.

paulsmits1

I have a 08 RX350 and have experienced the same problem. It is very annoying, especially on long trips. It does not bother me on short trips. The dealer informs me that there is no fault with the system, so one has to continue adjusting manually.

redrocks

lol, "one has to continue adjusting manually"? That doesn't make it an "automatic climate control". While I can see if temp gets above your desired setting, then cool air comes in. But I'm talking cold air coming from the dash vent near both doors.

One would think that Lexus could have done better? Is there a variance on the temperature setting (eg, plus or minus 2 degrees is acceptable before warm or cold air kicks in)? As stated, my wife's 2002 Honda Odyssey has no problems maintaining temperature.

While mine is a 05 RX330 CPO, I can't imagine folks buying these vehicles new and accepting this problem as "normal". If I have my vehicle temperature setting at 76 degrees in the winter, I should be wearing shorts "inside" the vehicle.

Thank you for sharing your experience. Is this really the experience of all RX owners?

jfelbab

I don't have this issue on my vehicle. I drive in climate extremes from below zero to 100° and have not had that problem. I also take several long road trips every year. My temperature is very even. Take it to your dealer and see if he can't get correct this issue. FWIW, mine is an 04 RX330 AWD.

redrocks

jfelbab, thank you for the response. I' glad to hear that you're not having any issues. That's good news! Thanks again!