Notices
LS - 3rd Gen (2001-2006) Discussion topics related to the flagship Lexus LS430

AC not turning on - NO issue with Climate Control Unit

Thread Tools
 
Search this Thread
 
Old Mar 6, 2019 | 07:17 PM
  #1  
jayalaba's Avatar
jayalaba
Thread Starter
Driver School Candidate
 
Joined: Sep 2018
Posts: 21
Likes: 2
From: CA
Angry AC not turning on - NO issue with Climate Control Unit

Hello all,
My AC suddenly stopped and not turning on, (Buttons are not responding) Nothing at all. I ordered climate control and no luck with new one. All lights are in panel working. Checked all fuses and all are good. Any place or relay or part to check? Pleas guide or Advice. Thanks
Reply
Old Mar 6, 2019 | 07:43 PM
  #2  
Trilkb's Avatar
Trilkb
Pole Position
 
Joined: Dec 2018
Posts: 336
Likes: 40
From: Ohio
Default

Best to see if it still has refrigerant in it. If the low pressure switch is triggered it won't work. I'd start there first, then if it has refrigerant I'd take the belt off to make sure the compressor isn't locked up. From there look for fuses. After that you're looking at a failed sensor if all else checks out.
Reply
Old Mar 6, 2019 | 08:05 PM
  #3  
jayalaba's Avatar
jayalaba
Thread Starter
Driver School Candidate
 
Joined: Sep 2018
Posts: 21
Likes: 2
From: CA
Default

Hello Trilkb, The refrigerant is good. I have the meter and looks okay (Green). Are you saying, when low refrigerant the climate control button will not work at all? New to me. I thought the AC will work but we will not cold air.. Thank you. I will keep you update about the compressor lock.
Reply
Old Mar 16, 2019 | 06:20 AM
  #4  
z17112's Avatar
z17112
Driver School Candidate
 
Joined: Jan 2019
Posts: 17
Likes: 4
From: PA
Default

I'm assuming your car is the same as most cars. You state no issue with climate control but when you wrote

"I have the meter and looks okay (Green)"

I am confused. Assuming your meter is not AC gauges....check a common occurrence:

When refrigerant is low the pressure in the system is low.

When pressure in the system is low, the low pressure cutoff switch will not allow the AC compressor clutch to engage. The compressor pulley (which contains the compressor clutch) will turn, but the compressor will not turn. You may want to look on YouTube to see what a compressor clutch engaging looks like. The clutch inside the pulley also turns when engaged.

The easiest way to test is: With the engine off find the low pressure cutoff switch (usually on or near the dryer), carefully pull the electric connector off (it will have a lock tab), and jump the two wires in the connector plug you removed. Make a U shaped jumper wire out of a piece of wire. Solid wire is best.

Start the car and turn the AC on. If the compressor clutch engages and the compressor turns on when the connector wires are jumped (connected) the problem is low refrigerant (most likely) or a bad low-pressure cutoff switch.

The switch can also go bad and there may be plenty of refrigerant in which case you would then need AC gauges to verify. The switch can be replaced without losing refrigerant.

Last edited by z17112; Mar 17, 2019 at 04:44 AM.
Reply
Old Mar 16, 2019 | 09:13 AM
  #5  
jayalaba's Avatar
jayalaba
Thread Starter
Driver School Candidate
 
Joined: Sep 2018
Posts: 21
Likes: 2
From: CA
Default

Thank you for your neat explanation. I took to few auto repair guys and I am not sure did they follow the instructions you said. I will do it and keep you updated. Thanks brother.
Reply
Old Mar 16, 2019 | 09:17 AM
  #6  
Ricklin's Avatar
Ricklin
Intermediate
 
Joined: Dec 2018
Posts: 302
Likes: 30
From: Washington
Default

Pretty sure he is stating that the gauge on a can of 134 refrigerant is in the green. My advice would be the same as yours above. If the compressor is not actually turning the gauge reading is not meaningful.
Confirm your compressor is actually turning on. I have not worked on my LS A/C system, so I can't advise how easy it is to see if the compressor itself is turning when the A/C clutch is powered. When you switch on the A/C the compressor has an electric clutch on the front of the A/C compressor. That clutch spins the compressor when powered up. On most cars you can see the compressor start turning when the clutch is powered. Look behind the pulley between the pulley and the body of the compressor. Check Utube for examples. The compressor must be turning for the gauge reading to be right.
Reply
Old Mar 16, 2019 | 11:22 AM
  #7  
jayalaba's Avatar
jayalaba
Thread Starter
Driver School Candidate
 
Joined: Sep 2018
Posts: 21
Likes: 2
From: CA
Default

Lets talk about the correctional way, I start the car, The buttons are in the climate control not working. No Air, No sound, No temperature, no display, nothing. I replaced with new but same result. Why should I check the compressor? The compressor will act or engage and follow the commandos from climate control correct? Please correct me if I am wrong. Thanks.
Reply
Old Mar 16, 2019 | 11:27 AM
  #8  
kos's Avatar
kos
Advanced
15 Year Member
Liked
Loved
Community Favorite
iTrader: (1)
 
Joined: May 2006
Posts: 658
Likes: 128
From: Arizona
Default

So what's actually bad here, the AC Control Unit? First post says "all lights in panel are working" but your last post says "no display, nothing. I replaced with new but same result."
Reply
ClubLexus Stories

Celebrating Lexus & Toyota from Around the Globe

story-0

10 Lexus Designs That Have Aged Like Fine Wine

 Verdad Gallardo
story-1

8 Tips for Improving Your Hybrid or Plug-in Hybrid's Efficiency!

 Michael S. Palmer
story-2

10 Best Lexus Models No One Remembers

 Joe Kucinski
story-3

TRD Off-Road Premium: Best 2026 4Runner, Except This One Thing

 Michael S. Palmer
story-4

Top 10 Lexus & Toyotas to Drive Before You Die!

 Joe Kucinski
story-5

Top 10 Lexus/Toyotas With The LEAST 5-Year Depreciation

 Joe Kucinski
story-6

Lexus LC500 Convertible Auction: A Preview of Rising Values?

 Brett Foote
story-7

GX 550 vs TX 550: Best 3-Row Luxury Lexus Family Hauler

 Michael S. Palmer
story-8

9 Best Lexus Models You Can Buy for Half Price (And 1 You Shouldn't!)

 Joe Kucinski
story-9

2026 Lexus NX Buyer's Guide: Models, Features, Prices & More!

 Brett Foote
Old Mar 16, 2019 | 11:39 AM
  #9  
jayalaba's Avatar
jayalaba
Thread Starter
Driver School Candidate
 
Joined: Sep 2018
Posts: 21
Likes: 2
From: CA
Default

NO display in the led panel, like direction of air symbol, vent symbol or any other displays. Please refer the pic. But I do have the lights around the unit.

This is courtesy pic. NO the real one from my car
Attached Files
File Type: pdf
led.pdf (37.8 KB, 110 views)
Reply
Old Mar 16, 2019 | 11:46 AM
  #10  
jayalaba's Avatar
jayalaba
Thread Starter
Driver School Candidate
 
Joined: Sep 2018
Posts: 21
Likes: 2
From: CA
Default

The actual bad is not the unit. could be some fuse, relay.. I have no idea..
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
staygold
LS - 1st and 2nd Gen (1990-2000)
4
May 23, 2019 02:02 PM
ep9716
SC - 1st Gen (1992-2000)
7
Aug 27, 2009 10:09 AM
SC_Edgar
SC - 1st Gen (1992-2000)
12
Jul 25, 2009 01:15 PM
drifter180
SC - 1st Gen (1992-2000)
5
Jun 20, 2008 01:14 AM
sc300jon
SC - 1st Gen (1992-2000)
1
May 17, 2001 08:11 AM




All times are GMT -7. The time now is 09:14 PM.

story-0
10 Lexus Designs That Have Aged Like Fine Wine

Slideshow: Some luxury cars chase trends, but these Lexus models look better now than they did when they first rolled into showrooms.

By Verdad Gallardo | 2026-05-06 17:58:29


VIEW MORE
story-1
8 Tips for Improving Your Hybrid or Plug-in Hybrid's Efficiency!

Slideshow: How to Get the Best Fuel Economy with a Hybrid and Plug-In Hybrid!

By Michael S. Palmer | 2026-05-05 20:54:44


VIEW MORE
story-2
10 Best Lexus Models No One Remembers

Slideshow: 10 best Lexus models no one remembers.

By Joe Kucinski | 2026-05-05 17:33:28


VIEW MORE
story-3
TRD Off-Road Premium: Best 2026 4Runner, Except This One Thing

Slideshow: diving into 4Runner TRD Off-Road Premium's pricing, performance, fuel economy, features, and amenities!

By Michael S. Palmer | 2026-04-23 13:09:18


VIEW MORE
story-4
Top 10 Lexus & Toyotas to Drive Before You Die!

Slideshow: the 10 Lexus and Toyota vehicles you need to drive before you die.

By Joe Kucinski | 2026-04-23 10:34:24


VIEW MORE
story-5
Top 10 Lexus/Toyotas With The LEAST 5-Year Depreciation

Slideshow: Top 10 Lexus/Toyota models with the lowest 5-year depreciation rate.

By Joe Kucinski | 2026-04-08 12:19:06


VIEW MORE
story-6
Lexus LC500 Convertible Auction: A Preview of Rising Values?

The LC hasn't even disappeared from the Lexus lineup yet, and we're already seeing signs of an explosive market.

By Brett Foote | 2026-04-06 09:25:02


VIEW MORE
story-7
GX 550 vs TX 550: Best 3-Row Luxury Lexus Family Hauler

Slideshow: comparing the pricings, specs, power, fuel economy, fun-factor, and features of the GX 550 Luxury+ and TX 550h+ Luxury.

By Michael S. Palmer | 2026-03-19 13:44:11


VIEW MORE
story-8
9 Best Lexus Models You Can Buy for Half Price (And 1 You Shouldn't!)

Slideshow: 9 best Lexus models you can buy for half price and 1 you should avoid

By Joe Kucinski | 2026-03-19 12:01:07


VIEW MORE
story-9
2026 Lexus NX Buyer's Guide: Models, Features, Prices & More!

Here's everything you need to know about the latest NX.

By Brett Foote | 2026-03-19 11:56:59


VIEW MORE