my a/c was freezing the past couple of days but yesterday it wasnt blowing cold air at all....i would put it on 85 and bring it down to 65 and there is no change at all. I also noticed that when the a/c is on the light above it blinks..i had the a/c repaired 2months ago by a guy...he replaced this washer that was busted and refilled it with freeon.

 

Only if the engine ECU has commanded that the A/C compressor clutch be enaged and the compressor doesn't turn.

 

when i turn the a/c on i hear a light psssssssssssss noise comming from the vents...i remember when i used to turn the a.c on i would hear that sound for 3sec and the air would turn cold...

can anyone explain how the a/c componets work... i really dont have a clue.

 

Check this out (some BS)

http://carpoint.msn.com/vip/usedrelo...model=LS%20400

Claims a known problem with the Lexus AC on 1st gen?


An occasional problem on this vehicle is failure of the Air Conditioning (A/C) Compressor Revolution Sensor.The cost to repair the A/C Compressor Revolution Sensor is estimated at $144.76 for parts and $117.00 for labor.All prices are estimates based on $65 per flat rate hour and do not include diagnostic time or any applicable sales tax.


Any truth here?

 

i also noticed today, when i started the car and let it warm up, and i put the a/c on the rpm drops from ~900 to 400 then goes up to 1,000 again...this never happened...could it just be a blet or something???

 

Old thread but here goes.

Heard some squealing from the engine bay a few days ago. Now when I put the AC on, the light blinks, rpms go up and then go right back down and the light just blinks. No AC.

Anyone know which component of the AC to look at first?

 

If this is it, I'd be pissed since I bought a brand new compressor and problem still persists; clutch still doesn't engage.

 

I called 3 dealerships and they do not have a part called Compressor Revolution Sensor. And I thought I could already fix my A/C!

 

No need to jump around replacing parts without a correct diagnosis.

By the symptoms you shared, it sounds like you have low charge again. Your static pressure is enough to signal the compressor to engage (that's why you get the sound at the vents), but as soon as the suction side pressure drops, the low pressure switch is tripping and giving you the blink. You can check for engagement of the a/c clutch after system has sat long enough to equalize the high and low sides. Engage a/c and go look for clutch engagement. If it does, your locked compressor safety switch on the end of the compressor is not the issue.
Colin

(a/c is easy. Ever spray an aerosol can down and notice how it gets colder to the touch?
Liquid that is depressurized will convert to a gas and absorb heat in the process. Liquid refrigerant is carefully depressurized expansion valve in the cabin air flow evaporator where it chills the air. The resulting depressurized gas is sent to the compressor where it is repressurized and it turns back into a liquid as it gives off heat in the condensor in front of your radiator. This process repeats continuously)