the dash wiring is more dense in the LX450 but the compressor contol portion of the AC should be the same.
A/C Compressor Problem
- Thread starter NorCalDoug
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I suggest going to the simple. That is the technician's first trick. Unplug the compressor wire and hook a jumper wire. Start the engine and touch the jumper to the battery + direct. Does the compressor kick in? If not, the clutch coil is gone. If so, work your way thru the system step by step until you find the problem. Jumper the output side of each relay and switch until you find the fault. That's how we do it in a shop.
P.S. If your first test to battery + kicks the compressor on, check freon pressure before continuing electrical checks. Low freon pressure will cut power to the compressor. Find the low pressure switch and bypass it with a wire. If that cures it then look for oily areas on hoses and connections indicating a leak. Also look inside the evaporater box in the dash. A leak can hide in there.
I don't think the pressure switch is all that sensitive/finicky. It may just be my pressure switch and experience, but it really doesn't take all that much refrigerant to activate the switch and turn the compressor on. IIRC, it came on with only 5-10 psi low side pressure once I started adding freon (you can hear it click on).
NorCalDoug
problems solved daily...
- Thread starter
- #25
There's plenty of refrigerant in the system -- in fact, it's a little on the high side.
Brian Macgyver said:
I agree starting with the a/c clutch jumpered direct to battery. This verifies that the clutch is working properly and engaging the compressor. If not, all the other testing and jumpers are in an effort to get it to engage - which will never happen. If this tests good, then move onto the pressure switch as others are suggesting.
I sure hope the dealership is working on this in their "spare time" and hasn't spent three full days on it. With a FSM and a little planning, it really shouldn't take more than a couple hours to start at the a/c clutch and work backwards through the circuit until you find the culprit component.
NorCalDoug
problems solved daily...
- Thread starter
- #27
Update: No real progress.
I took the wife’s LX 450 to the local Toyota dealership. Although I don’t particularly care for this dealership, I chose them because it’s about a half-mile from my office…I figured I could walk over and pick it up once they were done…
Anyhow, after tearing into the rig for 5 days, they’re not very close to solving the problem.
They suspect one of the following parts MIGHT be the culprit:
AC Automatic Amplifier (retail $577.82)
Or
AC System Amplifier (retail $235.10)
They’re really not sure.
So…I go to pick this thing up and am told that there’s a $364.00 charge for the work. I ask, “for what?” “I brought it in not knowing what was wrong with the A.C. and now you want me to pay $364 so that you can tell me that you don’t know what’s wrong with the A.C.?”
There’s a line of customers waiting to pay…not my problem. There are 2 cashiers, they'll get their cars eventually…the cashier looks at me dumbfounded -- she's not sure how to answer my question. There happens to be a quasi-manager, supervisor-type person at the cashier/vehicle pick up station…she intervenes. I ask her if she think’s I’m being unreasonable. Although she tries to hold the company line, she seems to be on my side. She calls the service-consultant-monkey asking him to explain the charge. His argument is that they spent many hours trying to figure out what the issue was and that they should be paid for that time.
I tell her that I do not dispute that many hours were spent trying to identify the issue, however, that time spent was of no benefit to me. I have nothing to show for their time spent. So...I am being asked to pay for…nothing.
To make a long story short (cutting out about 20 minutes of debate), I agree to pay for $164 which was the original estimate for an A.C. system inspection and flush…since they actually did flush and recharge the system. My gripe with this is that the service-consultant-monkey originally told me that the system was slightly OVERCHARGED, not undercharged as he wrote up, so the flush and recharge might not have been needed. However, it would’ve taken escalating a couple levels higher for me to possibly win this battle...not worth the hassle.
The entire time they had the vehicle, the service consultant dunce tried to tell me that the climate control system on the LX 450s are SO MUCH MORE COMPLICATED than what’s on a Land Cruiser. He didn’t want to hear that the 40th Anniversary LCs and the Collector’s Edition LCs have the same climate control system.
Now…off to my local Lexus service guy next to see what they tell me.
I took the wife’s LX 450 to the local Toyota dealership. Although I don’t particularly care for this dealership, I chose them because it’s about a half-mile from my office…I figured I could walk over and pick it up once they were done…
Anyhow, after tearing into the rig for 5 days, they’re not very close to solving the problem.
They suspect one of the following parts MIGHT be the culprit:
AC Automatic Amplifier (retail $577.82)
Or
AC System Amplifier (retail $235.10)
They’re really not sure.
So…I go to pick this thing up and am told that there’s a $364.00 charge for the work. I ask, “for what?” “I brought it in not knowing what was wrong with the A.C. and now you want me to pay $364 so that you can tell me that you don’t know what’s wrong with the A.C.?”
There’s a line of customers waiting to pay…not my problem. There are 2 cashiers, they'll get their cars eventually…the cashier looks at me dumbfounded -- she's not sure how to answer my question. There happens to be a quasi-manager, supervisor-type person at the cashier/vehicle pick up station…she intervenes. I ask her if she think’s I’m being unreasonable. Although she tries to hold the company line, she seems to be on my side. She calls the service-consultant-monkey asking him to explain the charge. His argument is that they spent many hours trying to figure out what the issue was and that they should be paid for that time.
I tell her that I do not dispute that many hours were spent trying to identify the issue, however, that time spent was of no benefit to me. I have nothing to show for their time spent. So...I am being asked to pay for…nothing.
To make a long story short (cutting out about 20 minutes of debate), I agree to pay for $164 which was the original estimate for an A.C. system inspection and flush…since they actually did flush and recharge the system. My gripe with this is that the service-consultant-monkey originally told me that the system was slightly OVERCHARGED, not undercharged as he wrote up, so the flush and recharge might not have been needed. However, it would’ve taken escalating a couple levels higher for me to possibly win this battle...not worth the hassle.
The entire time they had the vehicle, the service consultant dunce tried to tell me that the climate control system on the LX 450s are SO MUCH MORE COMPLICATED than what’s on a Land Cruiser. He didn’t want to hear that the 40th Anniversary LCs and the Collector’s Edition LCs have the same climate control system.
Now…off to my local Lexus service guy next to see what they tell me.
Doug,
Have you actually looked at the gauges while it was "operating"? I ask since everything seems to be okay, but you're not getting any cold. Could you have a blocked expansion valve? You should also see some bubbles in the sight glass when the compressor kicks in, even if it's not cooling--that would at least indicate that the compressor is doing something other than clicking and spinning.
I'm not up on the Lexi, but like you I have a suspicion that if you were to swap your working amplifier from the LC, you may be able to eliminate that problem (there are two of them?!).
Have you actually looked at the gauges while it was "operating"? I ask since everything seems to be okay, but you're not getting any cold. Could you have a blocked expansion valve? You should also see some bubbles in the sight glass when the compressor kicks in, even if it's not cooling--that would at least indicate that the compressor is doing something other than clicking and spinning.
I'm not up on the Lexi, but like you I have a suspicion that if you were to swap your working amplifier from the LC, you may be able to eliminate that problem (there are two of them?!).
I was going to suggest the same but assumed Doug would have noticed that the compressor was working. My expansion valve was blocked last year but it's also a pretty common problem and the dealer must have been smoking something if they couldn't diagnois a faulty expansion valve. However it's a good suggestion and it never hurts to take a step back and not get tunnel vision.
FYI - It's a pretty easy job if you do the grunt work yourself and get an AC shop to evac the system and recharge.
FYI - It's a pretty easy job if you do the grunt work yourself and get an AC shop to evac the system and recharge.
NorCalDoug
problems solved daily...
- Thread starter
- #30
the compressor is not coming on at all -- that's the problem. the question that seems to have eluded the toyota guys is why it's not coming on.
Doug are you interested in fixing this yourself?
NorCalDoug
problems solved daily...
- Thread starter
- #32
RavenTai said:
Yeah, if it's something that I can tackle. I don't have much in the way of electrical diagnostic tools.
Unless it means tearing apart the dash, I have no problems jumpin in and giving it a shot.
Do you have a suggestion?
Or did you already post on that I might've missed
do you have a multimeter ? familiar with the basics of its use?
NorCalDoug
problems solved daily...
- Thread starter
- #34
RavenTai said:
no multimeter. need to get one. need to learn how to use one.
more than willing to purchase one tomorrow and read/learn as I go.
Well you might be able to diagnose this one with just a piece of wire and a Test light,
There have been many posts in this thread that together cover just about anything that can be wrong with the system. Following those leads should get you to your problem.
The techs seam to think the AC AMP is not putting out its signal to start the compressor, with that info maybe start there and confirm weather they know WTF they are talking about, you could test it at the compressor relay, connector C16,
Looks like you might be able to get to it by removing the glove box, it will be up high you are looking for a relay that has:
1 orange wire,
2 green wires with an orange stripe,
1 green with white stripe
Pull the relay out, start the engine, take the piece of wire and short pin 4 (green with white stripe) to pin 2, (green with orange stripe) you have just bypassed the AC amp and the compressor relay.
If the compressor kicks in when you short the pin then it is possible that the AC amp or something it relies on is not right, or the compressor relay itself is bad,
If the compressor does not start then the AC amp is not your problem and you just saved $235
Do you have the EWD?
There have been many posts in this thread that together cover just about anything that can be wrong with the system. Following those leads should get you to your problem.
The techs seam to think the AC AMP is not putting out its signal to start the compressor, with that info maybe start there and confirm weather they know WTF they are talking about, you could test it at the compressor relay, connector C16,
Looks like you might be able to get to it by removing the glove box, it will be up high you are looking for a relay that has:
1 orange wire,
2 green wires with an orange stripe,
1 green with white stripe
Pull the relay out, start the engine, take the piece of wire and short pin 4 (green with white stripe) to pin 2, (green with orange stripe) you have just bypassed the AC amp and the compressor relay.
If the compressor kicks in when you short the pin then it is possible that the AC amp or something it relies on is not right, or the compressor relay itself is bad,
If the compressor does not start then the AC amp is not your problem and you just saved $235
Do you have the EWD?
NorCalDoug
problems solved daily...
- Thread starter
- #36
I have the LC EWD, not the 450 EWD.
Cruiserdrew
On the way there
Doug-I have a multi-meter you can use, however, you can buy an inexpensive one for $20. All you really need to know is continuity yes/no.
I hate stuff like A/C becuse I really do not feel confident tackling it myself. In this case, I would look hard at the A/C clutch, since it won't come on. Can you hear the solenoid click?
There is an auto air place on south Sunrise I used with my old car that was great, but I'm not sure if they are still in business.
I hate stuff like A/C becuse I really do not feel confident tackling it myself. In this case, I would look hard at the A/C clutch, since it won't come on. Can you hear the solenoid click?
There is an auto air place on south Sunrise I used with my old car that was great, but I'm not sure if they are still in business.
Doug, I don't have any technology input- only to give you the confidence to dig in - I am always daunted by the unknown until I get into it with the FSM and then once I see how logical it is laid out you can sus out the problems - besides this board has many smart people who want to help you too 
Doug,
R.T. is giving good techniques for eliminating some components as the cause, but without having an EWD in front of me I hesitantly say that it might be the wrong place to start. I still stand by the suggestion of starting at the A/C compressor clutch and jumpering 12v directly to it from the battery to verify that it engages. The dealer report does not seem to confirm that it was ever tested. Even RT's test is relying on the clutch to engage to "verify" the components. If the compressor clutch can't engage because it has failed, then it ruins the validity of all other tests. If RT has the jumper in a location that is electrically equivalent to jumpering directly, then I stand corrected, but I have no EWD to verify. Even so, I would still prefer a direct jumper to eliminate the possibility of a broken wire or bad plug connection somewhere.
R.T. is giving good techniques for eliminating some components as the cause, but without having an EWD in front of me I hesitantly say that it might be the wrong place to start. I still stand by the suggestion of starting at the A/C compressor clutch and jumpering 12v directly to it from the battery to verify that it engages. The dealer report does not seem to confirm that it was ever tested. Even RT's test is relying on the clutch to engage to "verify" the components. If the compressor clutch can't engage because it has failed, then it ruins the validity of all other tests. If RT has the jumper in a location that is electrically equivalent to jumpering directly, then I stand corrected, but I have no EWD to verify. Even so, I would still prefer a direct jumper to eliminate the possibility of a broken wire or bad plug connection somewhere.
Bruneti, I don’t think there is a right or wrong way to start on this, I recomended starting with jumping the compressor relay only because it tells Doug weather the AC AMP is bad or if the problem is somewhere (anywhere) else.
If the compressor engages the AC amp (or compressor relay) is bad as the Toyota techs say.
Starting with the compressor is just as valid, and is easier to do, I am with DesertDude I think if Doug jumps in he will find his problem, perhaps getting past the start is the hard part, if the reduced effort (no dash to take apart) of starting with the compressor gets Doug started then that is great.
Look at post # 36 for the relevant portion of the EWD
If the compressor engages the AC amp (or compressor relay) is bad as the Toyota techs say.
Starting with the compressor is just as valid, and is easier to do, I am with DesertDude I think if Doug jumps in he will find his problem, perhaps getting past the start is the hard part, if the reduced effort (no dash to take apart) of starting with the compressor gets Doug started then that is great.
Look at post # 36 for the relevant portion of the EWD
