A/c Sometimes Blows Warm Air

[amadesian]

Hi All,

I apologize if this question has bewen asked before.

I have a 2005 LS430 and the A/C will sometimes blow warm air. If I turn the a/c on and off enough, it will eventually blow cold air.

I took the car in to have it checked out and was told the compressor was bad and will need to be replaced. Along with the compressor, the expansion valve will also need to be replaced, and because of the debris in the system from the bad parts, the system will need to be flushed and re-charged. All this to cost, after a discount, $1900.

My daughter had a Honda Civic with the same problem. It was eventually learned that the relay switch in the compressor was bad. I was told replacing the compressor switch (not the whole compressor)solved the problem.

Is it possble to have the same problem witht my LS430? Any thoughts or suggestions would be greatly appreciated.

Art

[matchesls]

Either one is possible. I lost a compressor on one of my trucks and I had the same symptoms you describe. It was the clutch that went bad and it actually started to smoke when the A/C was turned on. When it's blowing warm open the hood and see if the clutch is engaged, if it's turning with the belt, it's engaged. If it is and blowing warm, the compressor is on and not working correctly. You can typically tell if the compressor comes on because it puts a load on the engine.

[amadesian]

Thanks for the response. Sorry, just to make sure I understand. The clutch is engaged when turning with the belt, if it is not turning with the belt, it is not engaged? All while the a/c is on, correct?

If the clutch is not turning with the belt, while the a/c is on, and it is blowing warm air, it is likely a bad clutch? Is that a repairable item? Or does it require replacing the whole compressor?

I believe I can do repairs as long as I don't have to open the system. I am not experienced, or have the proper tools for testing pressure, or recharging the system.

[matchesls]

With the car running and the A/C on, the clutch will be turning with the belt. You can have someone turn off and on the A/C while you watch the clutch engage/disengage. If it is not, it could be the relay, if not the relay, that would mean that the clutch is slipping and you would typically smell it burning. That is what happened to me, mine began to slip, the air got warm and I could smell the clutch getting really hot from slipping. I have also seen the bearings go bad on them but that usually means grinding noises and some sparks associated with that. I am not sure but the clutch can sometimes be replaced, but in our disposable society, it might not be available for replacement.

[matchesls]

I have the FSM for an LS400 up to the year 2000, and it shows that the clutch can be replaced but the compressor would need to be removed from the car to do so. This means discharging and recharging the system.

[Ancdmd]

I had the same problem in my '02, my a/c would blow warm air for about ten minutes then suddenly start blowing cold. It took a couple years to finally diagnose it correctly, something inside the compressor was sticking and preventing it from circulating refrigerant. The problem would occur frequently or just occasionally, but was never predictable. I got a new Denso compressor online for about $325 and had my independent tech replace it along with the accumulator, labor was a couple hrs. I'm not so sure you need to change the expansion valve. A/C has worked perfectly since.

[amadesian]

Thanks for the follow up. I am going to get a second opinion from another repair shop. If it is the same, I will probably take the same path.

Any suggestions for online parts?

[Micah.Berry]

I really like Sewellparts.com. I saw your compressor for $1162 there. Not exactly cheap - considering that includes forum discounts...

[Ancdmd]

Got the OEM Denso unit on eBay for about $325 shipped