Instrument cluster clock/climate control

[TexasLexus94]

Ah. life is good. Got the Air Bag light to turn off following the instructions from Lexls. Funny thing is that I needed to do the same thing about 2 years ago (not sure why, too old), and used the same instructions back then. I sent Lex 10 bucks as a thank you-never thought I'd need to use the same instructions again. Great forum...

[logic]

Does anyone know where to get a good used or rebuilt clock/climate control for 92' LS 400? The LCD display turning black seems to be a very common problem. I have checked with many auto-wreckers, they either don't have any left or are in the same condition (turning black). I had heard there were some retired Air Force personnel in California that rebuilt them.

PS: Given the number of problems, one might think that Lexus would step in and do a recall or sell rebuilt units, $800+ for a new one is a bit steep. thanks, bob

Order a LCD from from www.lextreme.com for $170.00 and follow the instructions. Take your time and you will be happy with the results.

[logic]

here is the picture..

Walter.

Some people find fault in everything, I guess you would rather look at a black ink spot than have your temp and time out of alignment. People never cease to amaze me.

[ducatist4]

I am replacing the 7 backlight lights on my climate control. I orderd them from superbrite. A sulvania T 1.5. They did not fit as per the tutorial. I ended up ordering from Jim Walker.

[Seagrass]

Can the blacked out tach and speedo needles be repaired by replacing the capacitors mentioned in several posts? I'm comfortable with PC board soldering (former NASA tech) and don't want to paint the needles.

[Davidliang]

I have same problem and same question as Seagrass.

And still waiting the result from RFeldes (Conductive paint method).

[CUMan]

I have same problem and same question as Seagrass.

And still waiting the result from RFeldes (Conductive paint method).

No, the capacitor repair does not fix the darkening needles. There is a conductive substance on the back of the needles which tends to crack as the needles age. When this cracks, the electrical circuit which provides the illumination is broken.

The only repair is to replace the substance (whatever it is). Jim Walker, who has been mentioned numerous times in this thread regarding his capacitor replacement work for the non-illuminating dashes, also does repairs to the darkening needles. Contact him.

[Davidliang]

I am curious, why a crack connection will damage the electrical circuit, and can't be fixed? I am a EE engineer.

If someone can fix it, its mean that the needle can be repaired or replace.

So why only JIM WALKER can fix it and we can't? only he can get the parts or he have special skill?

I am just wandering why no one fix the needles themself? is there any?

Thanks

[CUMan]

I am curious, why a crack connection will damage the electrical circuit, and can't be fixed? I am a EE engineer.

If someone can fix it, its mean that the needle can be repaired or replace.

So why only JIM WALKER can fix it and we can't? only he can get the parts or he have special skill?

I am just wandering why no one fix the needles themself? is there any?

Thanks

The material flakes off the back of the needle, and this breaks the circuit.

If you are an EE, figure out what the material is and offer a repair service. Obviously, Walker was able to do this. But he does not share his info with other people. I can't really blame him for this. He has a good business going, and he provides excellent service.

[Seagrass]

I am curious, why a crack connection will damage the electrical circuit, and can't be fixed? I am a EE engineer.

If someone can fix it, its mean that the needle can be repaired or replace.

So why only JIM WALKER can fix it and we can't? only he can get the parts or he have special skill?

I am just wandering why no one fix the needles themself? is there any?

Thanks

The needles can be purchased for $75 each but I suspect this is pc board component issue. I read on here or another Lexus site that needles that are almost completely dark are harder to repair ... if the problem is the coating or material then that wouldn't seem to make a difference. I think Jim and Mr Whizard provide a valuable low cost service compared to the dealers, and judging by the number of satisfied customers and cheerleaders they must do a great job. However, in the spirit of owners helping fellow owners I think I might inclined to share the info ... maybe not :)

[Davidliang]

I think that is not PC board components problem, or else needle should balck out completely.

I guess the PC board side will generate a high voltage, and on the back of the needle there have two condutive material at the two edges connect to the high voltage; the high voltage will engage the cold cathod needle.

The needle will partially black out depend on where the conductive material break(crack); if crack at the neck of the needle then it will fully black out.

So if I can patch the crack part it should restore the light.

This is my guess; I have only one car, I am not dare to take it apart unless I am sure I can fix it.

So I will gather more info before I start to fix it.

[Chief]

Does anyone know where to get a good used or rebuilt clock/climate control for 92' LS 400? The LCD display turning black seems to be a very common problem. I have checked with many auto-wreckers, they either don't have any left or are in the same condition (turning black). I had heard there were some retired Air Force personnel in California that rebuilt them.

PS: Given the number of problems, one might think that Lexus would step in and do a recall or sell rebuilt units, $800+ for a new one is a bit steep. thanks, bob

Last year I faced the same problem with my 94 LS400. I searched around on this web-site and found a reference to a gentlement named Jimmie Walker. He sent me a detailed write up on symptoms which I am attaching. The long and short of it is that he sent me instructions on how to remove it, and if you are somewhat handy, you can do it. It isn't easy releasing the electrical connections for someone who doesn't do it for a living, but I eventually got the dash light system out. I sent it to Jimmie, and as promised I got it back quickly (under 10 days). I re-installed it a year ago, and I have not experienced any problems. The cost was $225 or so.

I dont' know if there are others that do the same, but I will vouch for Jimmie, he did a great job!!!

Here are the symptoms he sent with his note:

No dash lights

Flickering dash lights

No or flickering dash background lighting

One or more needles not lit or dim

Fuel gauge sometimes won't work (shows empty)

Fuel gauge is slow to come up and never reaches the full mark

Climate control LCD won't display

Climate control button LEDs won't light or flicker in tandem with dash light flicker

Some of the small lights on the center console are intermittent

Dash lights take a long time to come on

Dash lights only work when it's warm or hot

The odometer does not accumulate miles sometimes

The problems seems to be temperature related

The problems are more evident in colder weather

Jim Walker

EMAIL ADDRESS: jimlwalker@sbcglobal.net

[HomerTHX1138]

Jim Walker does good work and fixed my dash lights and fuel gauge.

Regarding the "ink blot" LCD climate controls, mine display perfectly when the car and dash are hot. Perfectly. As they get colder the ink blot effect occurs. I recall seeing someone saying when this is the symptom replacing a few cheap capacitors cures the problem.

Does anyone have capacitors to replace and/or a how to?

[BlackGold'94]

Hi Jim,

My 93 LS 400 has Instrument cluster blackout when cold but comes on after 20 minutes or so. Also has outermost section of the tach needle blacked. Dealer says its a " lighting computer" that can be replaced cost $2000 parts only plus labour!

Please help - how do I get a copy of Jim Walker/motjebben replacement procedure?

Alan Morris amorris@kingsgate.ca

[PrlWhtLS400]

Hope this isn't comment abuse, but this forum directs you to a higher temp range lcd replacement for about $160.00, only thing is you have to replace it in the climate control unit yourself, tutorial is included on how to do this. Thought it was rather intresting.

Link to tutorial and LCD replacement screen information.

http://www.lexls.com/tutorials/lighting/cl...eLCDscreen.html

Link directly to place to order replacement LCD screen.

http://www.lextreme.com/lcdtech.html

Hope this helps and sorry if it ends up being a double post.

[renewabill]

Jim Walker does good work and fixed my dash lights and fuel gauge.

Regarding the "ink blot" LCD climate controls, mine display perfectly when the car and dash are hot. Perfectly. As they get colder the ink blot effect occurs. I recall seeing someone saying when this is the symptom replacing a few cheap capacitors cures the problem.

Does anyone have capacitors to replace and/or a how to?

HomerTHX1138,

It sounds as if your car has/had both lighting problems mentioned in this thread. That is the dashboard illumination and the climate control LCD blackout (or ink blot effect). I have been living with both these minor irritations for a couple of years and I'm getting ready to do something about them. My climate control LCD displays the same symptoms you mention, visible when hot, black when cold. I am capable and enjoy tinkering so I will attempt the LCD blackout solution myself, buying the LCD module from lextreme or Jim Walker. However, I am a little confused about the dash light problem as I look for the cause. The specific problem my car has is that both the speedo and tach needles went completely dark at about the same time (temp and fuel are OK). As I read through the thread, noticing what "Davidliang" had to say, it strikes me as odd that BOTH needles should fail at the same time (btw, LCD also failed only weeks before), especially if the reason for failure is a crack in the conductive material near the base. What are the chances they both fail at the same time and the same location on the needle? Is it possible that a capacitor(s) has any thing to do with both problems? Or something else? Please forgive my ignorance if this is a stupid question. I am not educated about electrical concepts.

If the problem has nothing to do with capacitors or another electrical problem and replacement needles will last many years, I guess I can just replace the needles...??

"Seagrass" informs us that replacement needles can be had for $75. Does anyone know where they are available?

Thanks to any and all,

renewabill

[jimmys]

I got mine on ebay for $100. it came with instructions how to solder. Took me 20 min to replace. its been 8 months now still good. If you now how to solder. cheapest way to go.

[bm1139]

hi guys, have posted regarding my plight few weeks back but it seems that im not getting any answers..i have done a diy on the clusters..(changing of the caps212,142,147) and now whenever i switch on the headbeam,the backlight of the temp/aircon/cd panel would go off)..any suggestions or anyone be kind enough to share with me a wiring diagram for my troubleshooting on the cluster...please..(my cluster's code g4-83010-50540)..thanking in advance.

[mangi1]

First I must tell you that I am an electronic technician that have worked with electronics (faultfinding/repair on component level) for more than 30 years and I live in Sweden.

By the information I found on internet I understand that there is some DC/DC or DC/AC converters mounted to obtain high voltage for the light-tubes on the instrument panel.

I know from my own experiences that those aluminium smd capacitors does not last for very long!

I shouldn`t have any problem of exchanging them.

BUT the only problem I have is that the needle for the speedometer went of today (only lit ¼) and I wonder if this is really related to bad capacitor or if I have to exchange the tube that lights up the needle. It is sometimes “flickering” like it is about to lit but it does not lit up fully.

I have not found any information about this “lamp” or how it is done to exchange it.

Another issue is that some of the bulbs for the buttons and display (radio and AC) is broken and I would want to know the voltage and amps for the bulbs ( 12-14V 20-80 mA ?) so that it will be “back to normal” again.

[pishta]

Sounds good. I plan on changing my backlights with the bright white ones they have. I probally wont be changing it anytime soon though, I don't want to get myself into it until it's needed. Thanks for the info.

<{POST_SNAPBACK}>

Here's some info on your needles and what is happening. First, this is what you would see if you could freeze the flickering in a dead standstill:

http://www.lextech.org/images/needlesandna...edlecloseon.jpg

The reason for this is here:

http://www.lextech.org/images/needlesandna...eheatdamage.jpg

Heat damage. non repairable, non reversible. BUT replaceable

Now, first let me say that if there are any questions from this post feel free to email me at sales@lextech.org, however I am going to try and be very specific so "everyone" reading can benefit.

You ask why your needles don't give you as much trouble with the headlights on. Try this experiment here:

go outside and turn your dimmer switch just off of the high position click (full on) down with your headlights off. Didnt make a hill of beans difference did it? NOW keep it in that position and turn the headlights on.

They dimmed! That's because the headlight circut will activate the second stage in the dimmer module when on and cut exactly .5 volt from the cluster. This is JUST ENOUGH to give the led's a slight break from "full voltage". That dimmer module is not just a knob, inside are a few chips and some diodes that regulate two lines to the cluster. one of them is full on (no headlights) one is controlled on (headlights on) which no matter what you do will always keep the cluster at .5 volt lower than the other way.

Why? Lexus didn't actually plan on this to happen (actually nippendenso since they make the unit). It is simple electronic theory, more easily said "it's the way it is" . See, whan you add a diode inline it drops the voltage of the line exactly .5 to .6 volt. This is one of the characteristics of the diode in an electronic circut. It just happens that you can see this little quirk of electronic technology since the needles that are sufficiently damaged are leaning on the brink of self destruction if that little tiny amount of energy is applied and helps finish overheating them.

You guy's wanna know the truth? That .5 volt extra is exactly what does the needles in...Nippendenso designed the clusters to run off of the dimmer module and never took into account what would happen if the headlights were off and bypassed the dimmer section #2 where the module kicks the diode in that saves the extra .5 volt. That's why they work fine with the headlights on.

In short......... Design flaw.

Why do the needles flicker?

-- They "dance" and flicker under the concept of the "flasher module" relay. If anyone has ever seen how a flasher module works, a small thin piece of aluminum is layed against a hot post when the post is "hot" it heats the piece of metal up and it bends away from the pole for about 1 second (just enough time to cool down and return). After the cool down, the metal returns to LS the pole and the process is repeated. It heats back up, pulls away from the pole and cools back down and returns. What you see..... is flashing! the contact touches, pulls away, then cools down and touches again. WHOLA! you have a flasher relay.

You also have a flasher needle too As the needle heats up it expands the contacts and they pull away. when they cool down about .4 tenths of a second later they come back, touch again, and bounce back off from expansion by the heat.

You basically have a flasher relay going on not by your choice. What this looks like, is a "dance" in the needle.

This should clear things up and if you need to ask anything else please feel free to email, I will be happy to help. It helps to get answers from an Engineer rather than a Technician. Techs just open units and replace parts, don't know why they failed, don't care, can't prevent it in the future.

Fortunately LLS is made of engineers and every concept is a fully engineered redesign to prevent future problems.

OK, so my 92 LS needle are perfect for now, should I run them on the dimmer so they last longer? I can stand the slightly less bright needles if they last longer as I intend to drive this car for a long time, only 90K on it.

[Usman Shafiq]

Hi, This post is very informative, however ther are some queries to ask about some specific topic. If someone can help me then please send me a private message. Thanks,

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[wonderwind]

Hello all. This post may be redundant, I didn't read ALL of the posts in this thread, so my apologies if it is.

I have a '93 LS400 and my dash lights had gone finally black after taking longer and longer to come on and also the tach and speedometer were intermittent until engine fully warmed up. I saw in the UK forum, a posting about replacing three cheap electrolytic caps and I tried it and voila! I had my lights, but the tach and speedo were still acting up. So I figured since the symptoms were similar, misbehaving until engine warm-up, there were other caps that may be suspect. I had ruled out the vehicle speed sensors because they aren't the type of things that would be temperature sensitive. So I pulled out the dash cluster again and replaced all of the canister type electrolytic caps. Well, I am happy to report that my dashboard is now 100% functional.

Advice to anyone trying to do this:

1. Be very careful and never force a cap off; I got impatient on one cap and pulled some of the wiring off the PCB which I remedied with a hot glue gun.

2. If you don't use exact replacements ( aluminum cans) and intend to use the Radioshack electrolytics which are much larger, lay them as flat as possible otherwise they will stick out and not allow the back cover to sit flush, in which case you may have to drill holes to let them poke out. I took this lazy route and now have 3 holes in the back panel but I don't care as I don't have to look at the back and no wires are exposed.

3. Mind the polarity on the electrolytics.

Sorry if I wasn't clear about the tach and speedo. My issue is not with the needle lighting, the needles were stuck at zero until engine warmed up.

Good luck and thanks to everyone in this club.

[Beowulf]

So I pulled out the dash cluster again and replaced all of the canister type electrolytic caps. Well, I am happy to report that my dashboard is now 100% functional.

This is good information, thanks!

Does anyone know for certain which caps are responsible for the sticky speedo and tach needles?

-B-

[bigdanpdx]

there's a guy on ebay that sells rebuilt climate controls I believe his reserve price is $150 plus $15 shipping and $100 deposit refunded when he recieves your old unit or you can have him rebuild yours and not pay the deposit;but your heat or ac wont work until its reinstalled.heres link as long as it lasts http://cgi.ebay.com/Lexus-LS400-Climate-Co...1QQcmdZViewItem

mine is flawless,it was really easy to install....the link doesnt seem to work;but if you do a search for ls400 climate you'll find it,the guy is J.Eichmann

[Bill67]

You can take this Unit out of the car yourself. Don't pay for the labour since they are charging $500 Canadian(assuming) for a reman part.

if you want me to direct you on how to do it, let me know.

My entire display panel ('94 LS400) is black. Was told I needed a new computer board??? Car works fine... just can't see odometer or velocity, etc. When you mention taking out reman part and getting it repaired - is the display panel what you're talking about?