squatch430

Hi Everyone!

Now that it is getting hot In Dayton I am turning attention to this problem of my 2004 LS430 with Nav. When I bought the car in April 2018 the temperature was in the 40's so I did not detect the issue.

In short, over the past weeks sometimes it worked, sometimes it did not.

Shortly after getting it home, I detected the issue and checked the refrigerant level. It was a bit low so I added a small can of juice and that topped it off. The day I did that I went on 4 or 5 short drives running around and the AC worked every time. I thought I had it.

The week after that, its performance deteriorated (when it worked, it worked great, but the frequency of it not working increased). I ran the AC diagnostics from the cockpit (procedure documented elsewhere in this forum) and it indicated no issues. When it was not working the compressor clutch did not appear to be going at all. I had assumed the system was protecting itself from a marginal compressor or the dryer was almost clogged up or both...

In the weeks since, I have resigned myself to the choice of me getting the system purged and replacing the compressor and dryer (my best guess of the issue), or taking it to a dealer. The price for parts is actually much cheaper than I expected, and being a licensed aircraft mechanic I am not afraid of the work, and I can replace a bunch of things before I match the cost of taking it to the dealer for just the diagnostics. I like tinkering anyways...I bought this because the LS430 is worth tinkering on...unlike the 2001 Ford Focus it replaced

Yesterday, I was pulling out of the garage and was closing the sunroof. The minute the sunroof closed I detected cool air the instant the sunroof hit the stop. Since then (and I have not opened the sunroof since then) the AC has worked.

My question is: Does your AC cut off when you guys open the sunroof? (Just because A proceeds B in time, does not mean that A causes B). I am trying to see if this was a coincidence or a clue in the mystery.

Thanks in advance!

2KHarrier

Hello and welcome from a fellow AMT. I work in ORD Line mtc with DAL.

The AC does not shut off on my 2001, and IIR correctly, my 2005 is the same.

Is it possible you have over-serviced the system? The over pressure switch will detect high line pressure and not allow the compressor to run.

Some diagnosing aids for you...
INDICATOR CHECK

1. Turn the ignition switch to the ON position while pressing the A/C control AUTO switch and R/F (Recirculation/ Fresh) switch simultaneously.

1. Check that the all indicators come on and go off 4 times in succession at 1 second intervals.

HINT:

• After the indicator check is completed, the system enters the DTC mode automatically.
• Press the "OFF" switch to cancel the indicator mode

REFRIGERANT

ON VEHICLE INSPECTION

1. INSPECT REFRIGERANT VOLUME

•  
  1. Check the sight glass on the liquid tube.

Test conditions:

• Engine is running at 1,500 rpm
• Single A/C: Blower speed control switch at "HI" position
• Dual A/C: Front blower switch at "HI" position Rear blower switch at "HI" position
• A/C switch ON
• Single A/C: Temperature control switch at "MAX. COOL" position
• Dual A/C: Rear temperature control switch at "MAX. COOL" position Front driver side temperature control switch at "MAX. COOL" position

Front passenger side temperature control switch at "MAX. COOL" position

• Fully open the doors

1. INSPECT REFRIGERANT PRESSURE WITH MANIFOLD GAUGE SET

•  
  1. This is a method in which trouble is located by using a manifold gauge set. Read the manifold gauge pressure when these conditions are established.

Test conditions:

• Temperature at the air inlet with the switch set at RECIRC is 30 to 35 °C (86 to 95 °F)
• Engine is running at 2,000 rpm
• Blower speed control switch is at "HI"
• Temperature control dial is at "COOL"

HINT: It should be noted that the gauge indications may vary slightly due to ambient temperature conditions.

1. Normally functioning refrigeration system Gauge reading: Low pressure side:

0.15 to 0.25 MPa (1.5 to 2.5 kgf/sq.cm)
High pressure side:
1.37 to 1.57 MPa (14 to 16 kgf/sq.cm)

1. Moisture present in refrigeration system

1. Insufficient cooling

1. Poor circulation of refrigerant

1. Refrigerant does not circulate

1. Refrigerant is overcharged or cooling effectiveness of condenser is insufficient

1. Air present in refrigeration system

1. Expansion valve malfunction

1. Defective compression compressor

Gauge readings (Reference)

squatch430

Wow! 1,000,000 thanks!

I did the diagnostic check within the cabin and everything was good. Just repeated it.

My gauge set came from my father, and it is pretty old (20 years or so, maybe). The Lo-Hi pressure readings were nominal when I filled it but will check again now it is working all the time.

But I am thinking that I might borrow another gauge set as an on-the-edge overpressure would certainly explain things. Except for the Sunroof (coincidence...). I am not going to touch the sunroof until I have another gauge set to check things, or it quits working again.

It has worked 10x in a row now...could be just enough has leached out it is now just under the edge...

Again, thanks for the data!

squatch430

I could not resist the urge...I cycled the sunroof several times and the AC operation was not impacted -- I bet it is (was) a bit too full and your intuition is correct!

Will confirm with another gauge set, once I find one...

2KHarrier

Looking forward to the results..

R-134a can be very unforgiving....

Oppie

Have you found the answer?
Having similar on off condition. Turn off car and restart it functions normal. I suspect a switch issue to the compressor. (car engine is cold when this happens)
Car has 100K first noticed 15 k ago . Bought last year with low mileage. Car like new outside and under the hood. Not a wear and tear but age.

Johnhav430

Dang that's great info!

aufenscuht

Hi guys! I will be honest, the last time I saw any LS in my shop was a lady w/ a LS400 that needed all major services (timing belt, seals, STARTER, etc, etc.)

As far as the A/C portion is concerned. You may have a clogged schrader valve-common in Jap cars. I would run dye through the system and inspect it for leaks. The area between the compressor and clutch could be leaking, use a sniffer on the condenser as well. Hope you get this solved, keep us updated!

biacs

I had similar issues. What I found is that these cars to have an anomaly of losing coolant over very long periods of time.

My coolant was low, and you need to pop off the cover to check radiator, but no biggie. I also replaced radiator cap, reservoir cap and the black hose that connects them.

Coolant has not dropped in over a year, and AC is ice cold. Our cars are all aging so assume common parts will fail, especially rubber seals.

squatch430

Sorry about the delay -- have been on travel.

I have not found a A/C Gauge set to borrow but might purchase one this weekend since I have a Harbor Fright coupon for same.

The A/C has bee performing flawlessly since my first post. It has been over 90 degrees most days and the car cools quickly and regulates temp well -- the controls and the actuators under the dash seem to be nominal as well.

Does not mean I am out of the woods. I suspect I have a slow leak somewhere. If I do, I will get some dye going to find it. I see that Harbor Fright has refrigerant sniffers on sale as well, so if I get to that point -- one cannot have enough tools! But first, I will check the pressure and report back what I find with another gauge set, but will not do so no earlier than this upcoming Saturday.

Oppie

The issue is not that it does not cool. The compressor appears to not function when first stated with AC off. Turning it on via function switch will not engage compressor. Then switching off the engine/ electrics and restart it will work correctly.

Oppie

Update on this issue ,Drained system (unintentionally) refilled with new fluid and sealant / lube . Has worked now for over a month without a problem.