foreste1

OK, I have posted a couple of times about this on my 03 GX, but today it was over 100 degrees and I was sitting for about 10 minutes and it happened....the warm air started coming in, even hot air since its 100 degrees out. I pulled hood up and the compressor was not spinning, and then a few minutes later it started spinning and the ac was cold again.
I had a code 42 a few weeks ago, so was thinking servo motor, but now that I can see compressor kicks off when it happens and it only happens when it gets over about 95 degrees outside and at idle (most of the year it will idle all day long and be ice cold) I am wondering what is getting hot and telling compressor to turn off, a switch? I had the ac evac and recharged a few months ago, and first they had it too low and I took it back and the said they had it perfect, could it be low and causing compressor to turn off when the compressor temp gets too hot for it at idle or a temp switch?? Its ice cold while driving even when its over 100 outside, its just when I idle and it may sound crazy but it seems like when its in direct sunlight it will do it.
Last, may just be crazy but my driveway is slanted somewhat and I could not get it to do it again when I got home and let it idle for 25 minutes and was about 103 outside, but then I put out on street on flat place and after a few minutes it did it, and I swear sometimes when I take a turn I feel the air get warm and back to cold when I straighten out.
I was taking to Lexus to have dash replaced soon and was going to pay them to diag, but I just feel like its something right in front of me....

foreste1

I feel like its either a temp switch shutting off compressor or the compressor is starting to go, but why would compressor run perfect all other times, only when it gets so hot outside does all this start happening. My fans are running as well.

EddieK05

Intermittent cooling is usually the evaporator getting frozen, so when it freezes you get warm air, then when it un-freezes, it gets cold again. I'll go cheapest ways to troubleshoot, I'd change the cabin air filter first if it hasn't been changed in awhile. If that doesn't solve it, it seems that somehow moisture(water) is getting into your A/C system. You'll need a leakdown test then. If no leaks, then it could be a block in evaporator drain or a bad expansion valve. Really, need to get it taken to a professional so that they can diagnose it. Continuing to run it in this setting can lead to more expensive problems, like a bad compressor.

foreste1

Thank you Eddie, I had originally wondered if it was expansion valve, and I asked Lexus when they replace dash how much extra labor to change that while in there and they said another $550 just labor, seemed pricey and was hoping it was not that. So do you know if there is a temp switch that would shut off compressor as I know I have no leaks and cabin air filter is new. I was going to buy a set of gauges this morning but not sure if they will tell me anything?

EddieK05

I'm sure there's an A/C temp. switch or sensor, but do not know for sure. I would think that when you took it to the A/C guy, they would have done a pressure/leakdown test. The switch or sensor could be bad, it should be a cheap part and easy to replace if you want to eliminate that, that would be an option.