elboy123

Hello to all, Im new to this forum and been having a difficult time finding what I need to find using the search tool. I have to problems with my recent purchase of the 2008 Lexus rx350.

First problem is with air conditioner. When turned on and set to Low (coldest setting) it blows fairly cold air, but when pressed up only once to bring it to 65 it starts to blow hot air, hot enough that leads me to believe the heater is engaged.

Second problem is with the fuse box. The fuse box under driver side dash has two rows of fuses. The first row of fuses all pass continuity test with circuit tester (light), but the second row of fuses NONE of the fuses light up, like if they were blown, but when I pull them out to inspect them they are all still good. One or two fuses in the fuse box in the engine compartment do the same thing.

Not sure if problem number one is related to problem number 2 but I could really use some help.

Thanks in advance to all.

thomas1

Need a schematic to follow the fuse path....But I would start with any blown fuses in engine compartment.

5W40

I don't think the fuse will cause the issue as you still have cold air blow out, symptoms that may be blamed on control module or air blend door motor or actuator if I may say.

Not quite familiar with your model, just my guess.

elboy123

I took the rx to get an ac diagnosis and the mechanic said I need to replace the Ambient Temperature Sensor and the Solar Sensor. The solar sensor is located somewhere under the hood and the ambient temp sensor is located under steering wheel by the right knee. Hopefully that fixes the problem, at least I have cold air for now

Thanks

Carver

Thanks for posting back with your resolution, much appreciated.

kiratthukr

I got the same issue on my 04 RX since yesterday.

AC started this weird behaivour after an oil change. Let us know if replacing the sensors worked for you.

elboy123

Problem solved!
After getting the AC diagnosis at the shop the mechanic gave me an idea where the cabin temperature sensor was located inside the car. I decided to take apart the plastic cover under the steering wheel and look around by the right knee area. Like I said I just recently purchased the RX so I wasn't really sure if this problem was going on before purchase. I did forget to mention that I had a remote start alarm installed 2 days after purchasing the rx. Sure enough I found the sensor without the wire connected, turns out the installers connected that wire on a empty slot and to them it all seemed fine. After I connected the wire were it belonged everything now works like it's supposed to.
Thanks guys