Posambique
Well-Known Member
- Joined
- Jul 2, 2014
- Messages
- 628
- Location
- Helsinki, Finland
- Car(s)
- Porsche 944 -86, BMW 323i Coupe -96
Ownership Verified: Four more litres of displacement ('92 LS400)
- Thread starter MXM
- Start date
Did a lot of things today.
Replaced oil, for one. The old oil was very very black. Noticed that the steering pump is leaking quite a lot, and it's sitting directly on top of the alternator, so the alternator is very wet. It's one of the "rare" typical issues for LS, not sure what to do about it yet.
Removed "the immobilizer" finally. Here it is, in its entirety :lol:
While in the mood for exploratory digging, I took the centre console apart and ripped the some aftermarket bits. This is some kind of handsfree system, it was wired into the audio system, not any more
While taking it apart, I noticed this infuriating detail. Whoever was installing the handsfree had lost one of the original bolts and replaced it with some off the shelf crap!
But.. later in the day I found the lost bolt behind the carpet
But now to the main story of today, I decided to tackle the needle illumination problem. This was the problem:
The rev counter needle is half-dark and the speedo needle is already fading at the tip. Now this is not your ordinary backlighting issue. Let me tell you how Lexus dashboard works.
As you know the dash is completely black until you turn the key. This is achieved with a matt black surface on the panel itself, and with a heavily tinted plastic screen in front:
Here is the screen removed, the matt black/grey surface makes everything that is not back-illuminated invisible. And the needles themselves are lamps! Yup, they are actual tinylightsabers CCFL tubes.
The backlight is also fluorescent. This produces a lot of light, so even with the tinted glass the dash is very clear.
The needles are encased in a conductive sheathe, with one side exposed. It cracks and peels off, making the needle go dark. I am not 100% sure how this works, but I assume it's some sort of capacitive coupling, this is why half the needle is lit, and it's only dark where the conductive layer is peeling off.
The matt surface is very delicate, so I slid a sheet of paper to protect it. If you put a greasy fingerprint on it, it might stay there. The needles themselves are also really fragile, so this was a bit of a fiddly work. First I used superglue to reattach the peeled-off layers.
And then I used conductive silver paint to paint over the cracks.
Speedometer needle too. It was mostly lit, but it was clearly on its way out.
Great success!
And once again, they didn't fuck around with "lateralization issues" as CrzRsn put it. The instrument cluster is also mirrored. LHD cars have rev counter on the left. What's more, even the hardware behind the cluster is mirrored, I was looking up for a pinout of the connector to the power module (CCFLs need high voltage and starter/ballast, so it's a separate module here), to test the gauges on the table, and the photo of an LHD cluster had connectors in opposite corners. So they designed even separate power PCBs, for the two versions that do EXACTLY the same function. They could've easily used the same part for both, with a difference that one of the versions would have a bit longer cables to plug to the opposite side. Boggles the mind.
Replaced oil, for one. The old oil was very very black. Noticed that the steering pump is leaking quite a lot, and it's sitting directly on top of the alternator, so the alternator is very wet. It's one of the "rare" typical issues for LS, not sure what to do about it yet.
Removed "the immobilizer" finally. Here it is, in its entirety :lol:
While in the mood for exploratory digging, I took the centre console apart and ripped the some aftermarket bits. This is some kind of handsfree system, it was wired into the audio system, not any more
While taking it apart, I noticed this infuriating detail. Whoever was installing the handsfree had lost one of the original bolts and replaced it with some off the shelf crap!
But.. later in the day I found the lost bolt behind the carpet
But now to the main story of today, I decided to tackle the needle illumination problem. This was the problem:
The rev counter needle is half-dark and the speedo needle is already fading at the tip. Now this is not your ordinary backlighting issue. Let me tell you how Lexus dashboard works.
As you know the dash is completely black until you turn the key. This is achieved with a matt black surface on the panel itself, and with a heavily tinted plastic screen in front:
Here is the screen removed, the matt black/grey surface makes everything that is not back-illuminated invisible. And the needles themselves are lamps! Yup, they are actual tiny
The backlight is also fluorescent. This produces a lot of light, so even with the tinted glass the dash is very clear.
The needles are encased in a conductive sheathe, with one side exposed. It cracks and peels off, making the needle go dark. I am not 100% sure how this works, but I assume it's some sort of capacitive coupling, this is why half the needle is lit, and it's only dark where the conductive layer is peeling off.
The matt surface is very delicate, so I slid a sheet of paper to protect it. If you put a greasy fingerprint on it, it might stay there. The needles themselves are also really fragile, so this was a bit of a fiddly work. First I used superglue to reattach the peeled-off layers.
And then I used conductive silver paint to paint over the cracks.
Speedometer needle too. It was mostly lit, but it was clearly on its way out.
Great success!
And once again, they didn't fuck around with "lateralization issues" as CrzRsn put it. The instrument cluster is also mirrored. LHD cars have rev counter on the left. What's more, even the hardware behind the cluster is mirrored, I was looking up for a pinout of the connector to the power module (CCFLs need high voltage and starter/ballast, so it's a separate module here), to test the gauges on the table, and the photo of an LHD cluster had connectors in opposite corners. So they designed even separate power PCBs, for the two versions that do EXACTLY the same function. They could've easily used the same part for both, with a difference that one of the versions would have a bit longer cables to plug to the opposite side. Boggles the mind.
Last edited:
Did a lot of things today.
Replaced oil, for one. The old oil was very very black. Noticed that the steering pump is leaking quite a lot, and it's sitting directly on top of the alternator, so the alternator is very wet. It's one of the "rare" typical issues for LS, not sure what to do about it yet.
Removed "the immobilizer" finally. Here it is, in its entirety :lol:
While in the mood for exploratory digging, I took the centre console apart and ripped the some aftermarket bits. This is some kind of handsfree system, it was wired into the audio system, not any more
While taking it apart, I noticed this infuriating detail. Whoever was installing the handsfree had lost one of the original bolts and replaced it with some off the shelf crap!
But.. later in the day I found the lost bolt behind the carpet
But now to the main story of today, I decided to tackle the needle illumination problem. This was the problem:
The rev counter needle is half-dark and the speedo needle is already fading at the tip. Now this is not your ordinary backlighting issue. Let me tell you how Lexus dashboard works.
As you know the dash is completely black until you turn the key. This is achieved with a matt black surface on the panel itself, and with a heavily tinted plastic screen in front:
Here is the screen removed, the matt black/grey surface makes everything that is not back-illuminated invisible. And the needles themselves are lamps! Yup, they are actual tinylightsabersCCFL tubes.
The backlight is also fluorescent. This produces a lot of light, so even with the tinted glass the dash is very clear.
The needles are encased in a conductive sheathe, with one side exposed. It cracks and peels off, making the needle go dark. I am not 100% sure how this works, but I assume it's some sort of capacitive coupling, this is why half the needle is lit, and it's only dark where the conductive layer is peeling off.
The matt surface is very delicate, so I slid a sheet of paper to protect it. If you put a greasy fingerprint on it, it might stay there. The needles themselves are also really fragile, so this was a bit of a fiddly work. First I used superglue to reattach the peeled-off layers.
And then I used conductive silver paint to paint over the cracks.
Speedometer needle too. It was mostly lit, but it was clearly on its way out.
Great success!
And once again, they didn't fuck around with "lateralization issues" as CrzRsn put it. The instrument cluster is also mirrored. LHD cars have rev counter on the left. What's more, even the hardware behind the cluster is mirrored, I was looking up for a pinout of the connector to the power module (CCFLs need high voltage and starter/ballast, so it's a separate module here), to test the gauges on the table, and the photo of an LHD cluster had connectors in opposite corners. So they designed even separate power PCBs, for the two versions that do EXACTLY the same function. They could've easily used the same part for both, with a difference that one of the versions would have a bit longer cables to plug to the opposite side. Boggles the mind.
God, I love the exacting attention to detail that Toyota/Lexus had with this car. Just knowing how much effort and care they put into the tiniest detail is just...wow.
Those gauges btw are great looking. Minimalist, white backlighting, nice needles. Perfection. Who needs a digital dash when you've got this?
ScarFace88
Forum Addict
- - - Updated - - -
Did a lot of things today.
Replaced oil, for one. The old oil was very very black. Noticed that the steering pump is leaking quite a lot, and it's sitting directly on top of the alternator, so the alternator is very wet. It's one of the "rare" typical issues for LS, not sure what to do about it yet.
Removed "the immobilizer" finally. Here it is, in its entirety :lol:
While in the mood for exploratory digging, I took the centre console apart and ripped the some aftermarket bits. This is some kind of handsfree system, it was wired into the audio system, not any more
While taking it apart, I noticed this infuriating detail. Whoever was installing the handsfree had lost one of the original bolts and replaced it with some off the shelf crap!
But.. later in the day I found the lost bolt behind the carpet
But now to the main story of today, I decided to tackle the needle illumination problem. This was the problem:
The rev counter needle is half-dark and the speedo needle is already fading at the tip. Now this is not your ordinary backlighting issue. Let me tell you how Lexus dashboard works.
As you know the dash is completely black until you turn the key. This is achieved with a matt black surface on the panel itself, and with a heavily tinted plastic screen in front:
Here is the screen removed, the matt black/grey surface makes everything that is not back-illuminated invisible. And the needles themselves are lamps! Yup, they are actual tinylightsabersCCFL tubes.
The backlight is also fluorescent. This produces a lot of light, so even with the tinted glass the dash is very clear.
The needles are encased in a conductive sheathe, with one side exposed. It cracks and peels off, making the needle go dark. I am not 100% sure how this works, but I assume it's some sort of capacitive coupling, this is why half the needle is lit, and it's only dark where the conductive layer is peeling off.
The matt surface is very delicate, so I slid a sheet of paper to protect it. If you put a greasy fingerprint on it, it might stay there. The needles themselves are also really fragile, so this was a bit of a fiddly work. First I used superglue to reattach the peeled-off layers.
And then I used conductive silver paint to paint over the cracks.
Speedometer needle too. It was mostly lit, but it was clearly on its way out.
Great success!
And once again, they didn't fuck around with "lateralization issues" as CrzRsn put it. The instrument cluster is also mirrored. LHD cars have rev counter on the left. What's more, even the hardware behind the cluster is mirrored, I was looking up for a pinout of the connector to the power module (CCFLs need high voltage and starter/ballast, so it's a separate module here), to test the gauges on the table, and the photo of an LHD cluster had connectors in opposite corners. So they designed even separate power PCBs, for the two versions that do EXACTLY the same function. They could've easily used the same part for both, with a difference that one of the versions would have a bit longer cables to plug to the opposite side. Boggles the mind.
The internal workings of the dash are quite interesting, my SC400 had a very similar setup with the same issue with the needles not lighting up.
Yup, isn't SC largely the same car in coupe form? I don't know how for how long they used this arrangement, but afaik ES and GS used LED for backlight and for the needles themselves.
Hard to say, but certainly more than bulb or LED backlight. In addition to custom sized fluorescent tubes you also need all that extra power supply to drive it. It certainly seems that they were doing it just for effect, and it those days fluorescent was the way to get the most light from the smallest size
- Joined
- Jul 15, 2007
- Messages
- 5,846
- Location
- Maribor, Slovenia, Europe
- Car(s)
- '89 BMW E30 325iT, '95 BMW E36 318ti compact
Amazing. Those engineers had a field day with this car.
Captain_Whine
Well-Known Member
ROight, just keep buying v8 cars into my face... 
Gotta say, i found this thread, scrolling google pictures on "LS400" :lol: World is too round for us lot to miss.
Any special plans on the exhaust?
Gotta say, i found this thread, scrolling google pictures on "LS400" :lol: World is too round for us lot to miss.
Any special plans on the exhaust?
Captain_Whine
Well-Known Member
Can i at least hold on for some "shopping trip" videos? 
(I'm actually looking on this as my next wheelset, since 'hunderbucket was denied/achived/sack'd...)
(I'm actually looking on this as my next wheelset, since 'hunderbucket was denied/achived/sack'd...)
ScarFace88
Forum Addict
Perc
Very Odd Looking Vehicular Object
If I recall correctly, my mom's Corolla had a similar gauge cluster. It was a 2004-2005 or something, last of the Corolla hatchbacks before it was revamped and renamed Auris. It might not have had CCFL, but it was dark until you started it up.
public
Captain Slow Charging
Trickle down electrics!
Posambique
Well-Known Member
- Joined
- Jul 2, 2014
- Messages
- 628
- Location
- Helsinki, Finland
- Car(s)
- Porsche 944 -86, BMW 323i Coupe -96
Next job: the dead LCD screen.
As mentioned earlier, I ordered a cheap replacement from ebay, not realizing that LHD and RHD are different :/
The LCD consists of basically 2 separate circuits, one for temperature and one for the clock, and they switch places depending on the version. I was determined to make it fit though, so I did. It was a terrible hack job to wire it, and I'm a little embarrased to embed the photos :lol: Please make sure there are no pregnant women or children around when you open the following images: 1, 2.
But here is the result. I'm not entirely happy with it, but it's better than a dead, solid black screen. RHD version would obviously have temperature digits lined up perfectly above the temp buttons, and the clock would be next to the clock buttons, but oh well. The screen is also unfortunately whiter than the other LCD screens, the glass itself on the original screen seems to have a slight brown tint. It's not going to be that apparent with backlight on, only when front-illuminated.
I've also messed up, and bought wrong backlight bulbs (some of the original ones were dead), they are very very dimm, so no backlight until I find the correct ones.
RHD screens are also available, but they are significantly more expensive. I paid 30? for the screen and delivery from China, but the cheapest RHD I can only find from US for 120? + delivery. It might be a better screen though, all of them are reproductions, anyway, can't get just the screen from Lexus.
As mentioned earlier, I ordered a cheap replacement from ebay, not realizing that LHD and RHD are different :/
The LCD consists of basically 2 separate circuits, one for temperature and one for the clock, and they switch places depending on the version. I was determined to make it fit though, so I did. It was a terrible hack job to wire it, and I'm a little embarrased to embed the photos :lol: Please make sure there are no pregnant women or children around when you open the following images: 1, 2.
But here is the result. I'm not entirely happy with it, but it's better than a dead, solid black screen. RHD version would obviously have temperature digits lined up perfectly above the temp buttons, and the clock would be next to the clock buttons, but oh well. The screen is also unfortunately whiter than the other LCD screens, the glass itself on the original screen seems to have a slight brown tint. It's not going to be that apparent with backlight on, only when front-illuminated.
I've also messed up, and bought wrong backlight bulbs (some of the original ones were dead), they are very very dimm, so no backlight until I find the correct ones.
RHD screens are also available, but they are significantly more expensive. I paid 30? for the screen and delivery from China, but the cheapest RHD I can only find from US for 120? + delivery. It might be a better screen though, all of them are reproductions, anyway, can't get just the screen from Lexus.
public
Captain Slow Charging
It looks alright! As long as you don't tell anyone how the readings should line up :lol:
samulis
Active Member
Nothing wrong with wiring, it works. Did you check that can you remove the tinted glass from old one? Might need some heating to soften the glue and don't see how it could be worst than new phone screens. You have the broken one to test.
Last edited:
It doesn't look like a separate layer, the glass itself that contains the liquid crystals has a tint. It could be due to age, but could be just a different type glass or polarizing layers.
