Jenju10

I have a 2008 RX 350 with 128k mi, automatic power steering.

My alternator and water pump were just replaced and as I left the mechanic shop, "check air conditioner" message was displayed on the navigation screen. The mechanic says freon is fine, and it is "hooked up" and that I'd need a new compressor. Problem is, I just had the A/C compressor replaced (by a different mechanic) just 3 years ago.
The heater works, the A/C does not work.
The mechanic says this is not his fault and it is due to my alternator going bad.
1. Is this a coincidence or am I not being told the truth?
2. What is the typical lifespan of an AC compressor?
3. Must the AC Compressor be removed in order to replace the alternator?

Any advice is appreciated - I am soon bringing the car back to him so he can "take another look at it", but would like to have some insight before I do.
Thanks in advance.

iolmaster

iTrader: (1)

I do not think the compressor has to be removed to get to the alternator.

Jenju10

Thank you for your response.

What could have caused this message to display with just a 3 year old ac compressor?

Nad1370

What was the cause of the first AC compressor to go bad?
You said your AC doesnt work. -- when you turn ON the AC button (car running at idle), does the AC light flash?

Did your mechanic tell you what actually failed on the current AC compressor?

Jenju10

Jenju10

Nad1370

This will be a quick check without needing a mechanic.
If your RX is equipped with a Magnetic Clutch Relay, most Toy/Lex have these, swap that out with a relay similar to that.
A one that you dont need to check the AC sytem.
Maybe a horn or Defogger relay.
Relay prongs should have the same count and placement.
These relay should be in a junction block under the hood.

Let us know if you're able to do this.

john341

This is a good suggestion. I will also check to see if the serpentine belt(good idea to change it, since it has more than 100k on it) is good or bad and if the mechanic tightened the tensioner to spec. AC light can flash when the belt is slipping also.

DennisMik

A point to be aware of is that there is a sensor to prevent the compressor from running if the ambient temperature is below 35º F. The system would freeze up if it did.

tomr51

does the clutch pull in when AC is switched on?

Audiqv8

Doesn't mean that the compressor is bad, it only mean that there is a problem with the AC. In order to change the alternator, the radiator has to be remove. This mean that the fan (used by the AC) has to be disconnected. There is also an AC line which also need to be slightly moved in order to remove the alternator. If the mechanic still insist on the compressor being bad, then I would go back to the mechanic who installed the compressor and have him verify that the compressor is bad.

Koolaid54

very common for the relay to go bad. try using a known good one.

if it still doesnt work. with the car off. use a test wire from B+ and jump the terminals in the AC relay connector in the fuse/relay box. if one of them doesnt make the AC click. then its time for a new AC compressor. If it does click turn on the car and put it on full AC...jump the same terminal and check to see if you have cold air. if you dont have cold air...time get the AC charged but you might want to have someone pressure test the system.

Red981

DennisMik

There is no replaceable relay for the a/c compressor clutch. It is built into the a/c amplifier control module. However, the codes you have do not indicate a compressor problem.

Code 21 is "Solar Sensor Circuit Passenger Side. The full code is B1421.
Code 24 is "Solar Sensor Circuit Driver Side. The full code is B1424.

Possible causes are:
1. Automatic light control sensor (A/C solar sensor)
2. Harness or connector between automatic light control sensor (A/C solar sensor) and A/C amplifier
3. Harness or connector between automatic light control sensor (A/C solar sensor) and body ECU
4. A/C amplifier
5. Body ECU

Since this info is from a service manual for U.S. cars, driver side and passenger side are probably reversed compared to your car. But since you have the code for both sides, you should look at what the 2 sides have in common. That would be items 4 and 5 in the possible causes list above.

There is a self diagnostic that you can run, but I think you would just be wasting your time because you already have codes. But here is a link to it anyway -
http://www.clublexus.com/forums/perf...eed-codes.html

​​​​​​​Scroll down to post # 11 for the procedure.

Nad1370

Those 2 codes are common to have.
Its the solar sensor for the auto temp.
Just means the solar sensors weren't getting direct sunlight.

Aside from the AC amplifier,
Could also be LOW on refrigerant.
You will need to hook up gauges on the high and low side line of the AC system
Or just have a shop look at it.
Do you remember if you ever had to recharge the AC system with freon?