1995 LEXUS GS300

Ok, I have read on the internet for days/weeks regarding my issue. This issue happened last year as last summer it was WAY hotter here than this summer.
This is the situation. During the day when its super hot out, my A/C will stop working---meaning when its over 90f degrees out the A/C light will blink meaning that the compressor shut off. It you click on it twice, it will turn it back on.
During the cooler nights, it will work without any problem. If you have meats, I can store them for you....it blows SUPER COLD!

So, this is not a issue that happens all the time at all. It is very intermitten.

I have ran OBD codes but none show up. Also, under the A/C climate control switch the codes that show up are #43. This I can say is NOT related because I cleared this code --than had the blinking happen again, than checked for codes again afterwards and found NO codes. So, maybe it is related, maybe it isn't. I can't say for sure, but I tested for error codes and found nothing immediatly after it happened.

I have searched the internet only finding ONE other person with the same exact problem. This person posted on 2carpros. I have not seen any response on it and have also not found any way to post on there..maybe something wrong with that forum..either way, no answers floating around.

The most difficult part in diagnosing this issue is that it doesn't happen often as it doesn't get hot enough here this summer. All other times it works the way its supposed to.

One last bit of information to add to the mystery, I found that when this happens, it will happen usually under acceleration (light & heavy--it happen under both).

I am hoping that someone here can help me with this issue. I have the lexus service manual for this car as well.

 

Had the problem in my 94. Heat creates resistance in wires. Once I cleaned up my grounds I never had the problem again. There is a bundle of wires white with a black stripe bolted to the fender well. I unbolted it and sanded down to bare metal with a dremel sand tool and reconnected it. Also check the other fender well and the negative battery terminal/ground at chassis.

The ECU sends a signal to the A/C every few seconds to make sure it's still there and functioning. Too much resistance and the signal doesn't make it and your car thinks it's malfunctioning and shuts it off.

 

Hey, That is a great idea! I sure hope this works. I did what you said yesterday and am now just waiting for another hot day about 90f. Maybe tomorrow will bring over 90F and I will be able to test this.

BTW, I did both the bundles of wires on both fenders. Not a whole lot of corrosion or rusting at all. I also sanded down to bare metal on both, sanded the screw, sanded the Apron (inner technical term of the fender) where it bolts to, and the wire end block. I also did the negative battery wire where it bolts to the left driver side (near the lower rail on the left apron) as well.

I sure hope this works as I have been chasing around this problem for a year and couldnt find an answer ANYWHERE!

Thank you so much for your advice and help.


I am so supprised that there isn't more people out there with this problem.

 

Okay, so MSN weather says 93 today in New York City, is your AC problem fixed?

 

Well, No issues here so far, but, it only reigstered on the temp guage 91 (on long island). One thing I will say is that the humidity is much lower then it usually is when this issue happens, but, I can say that all day today I had no problems at all.

I honestly thought, and still think in the back of my head that the magnectic clutch could be causing the issue, but, the issue has gone away.

BTW, the way these cars come from the factory, the ground points are full of paint..and I would think that it really doesn't matter a whole that ---saying to myself that it would be hard to screw up a grounding point. Needless to say, the issue as not come back (yet) and it doesnt look like there will be too many mroe hot days until next year....(thats unless I go to florida first!).

So, again, thank you so much for the advice as today I didn't melt!
I really do hope that it fixed the problem. The only concern that I have is that I really didn't see any type of rust on any of the points which makes me still feel uneasy about this being the end-all-be-all solution. I would think I would be removing rusted stuff. The screw however was oxidized a but (turned yellow-ish, not rust though) and i removed that with some sanding and sanded down the painted area on and around each hole.

Its almost unbelieveable that this worked, but at the current moment, its working! :-)

 

Okay, so, today the problem showed its ugly head again!
This time it was only once, although it wasn't really too hot today (about 91).

Here were the conditions in which it happened:
1. car was driven about 4 miles to a destination and sat for about 15 minutes before I returned to it.
2. The Auto A/c button was set to 65f and was left on when I left the car for the 15 minutes.
3. When I got back into the car, I turned it on and within a second, shifted into drive and took off HARD. (traffic was coming on the Highway--although its a more like a big multi-lane street with signal lights in this town)
4. Within seconds after that, the a/c light started blinking and warm air was blowing out of the vents.
5. After pressing the a/c button twice (once to turn off and again to turn back on) the problem didn't happen at all for the rest of the day, although there wasn't too much more driving done afterwards.

So, now I am back posting as much as possible help anyone out there help me.

All comments and suggestions are welcome!!

 

See my thread

https://www.clublexus.com/forums/gs-...y-working.html

 

Eh well it worked for me and it's over 100 for four months out of the year. Sorry about your luck.