Allow me to introduce myself: I'm Cthopkinssc from Florida . I
recently purchased a 1995 Lexus SC400. A project car for sure
but a labor of love. I would like to find the sensor which helps to
control the interior temperature. When I try to adjust the temp from
ice cold a/c to comfy, it blows hot air. I pulled the 1" square next to
the ignition to find empty space. The outside air temp display reads
-22F. Can someone show me where I can find this sensor and what
It looks like?- Thanks!

 

Welcome to CL. I have moved your tread to correct forum. We have a special section for SC owners. And in here you can find almost all answers you need.

 

The -22° reading most likely means your ambient temperature sensor is defective or its signal has been interrupted (broken wire or disconnected plug). It's located on the passenger side of the front grill. That's the value commonly stated when that happens.

Are you sure you had empty space behind the 1" square, not a little black housing and sensor that looks sort of like a LED? If that space is indeed empty, then you've got bigger problems... Someone may have removed important stuff in an ill-fated attempt to solve the problem.

 

Thank you! I should be able to get posts in the right place in the future. Peace!

 

Replaced outside sensor. Checked inside cabin sensor closer;seems to be there. Air temperature either ice cold or hot...

 

Got the chance to look behind the dash of my SC400. All connections intact but no sensor there. Could this be the reason why the a/c goes from ice cold to hot with the slightest adjustment?

 

Looked online for an inside air temperature sensor. No luck. Suggestions?

 

You won't see much behind the 1" square. The cabin air temp sensor looks more like a bulb than a sensor, and it's embedded in a dark chunk of plastic. At any rate, I don't think that explains your problem because it should only really come into play when running the HVAC on auto. Manual temperature adjustments wouldn't care about the temperature in the cabin. The heater control valve is the only thing I'm aware of that would explain your situation, although I suppose ECU issues (capacitor leakage) maybe could if it controls HVAC?

 

I have the exact same issue..

I have freezing cold AC when its on AUTO and the **** is set all the way to COLD, then the very first click to 65 degrees blows hot air, the same hot temp as when the **** is turned to HOT.

I had some work done on my stereo so the lower dash and panels were all removed recently, I bet its related. I'm going to make them repair or fix whatever happened so I'll chime back in with any helpful info in a day or 2..

 

Update on this.

The shop took everything apart and it's all plugged in and there but still not working. It's either ice cold or hot, no in between still. Any ideas?