Why are my needles dead or flickering? Answers inside!
10-25-04, 10:21 PM
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Why are my nedles dead or flickering? Answers inside!
Since i keep getting ask by 20 people per day why the needles are flickering or dead, here is the exact explanation for everyone.
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/needle...dlecloseon.jpg
The reason for this is here:
http://www.lextech.org/images/needle...heatdamage.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 at 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 ****, 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 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.
-Brian @ Lextech.
-Lead Engineer
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/needle...dlecloseon.jpg
The reason for this is here:
http://www.lextech.org/images/needle...heatdamage.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 at 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 ****, 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 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.
-Brian @ Lextech.
-Lead Engineer
Last edited by O. L. T.; 10-21-05 at 11:08 AM.
10-26-04, 11:04 AM
#3
Lexus Fanatic
Re: Why are my nedles dead or flickering? Answers inside!
Originally posted by L. L. S.
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/needle...dlecloseon.jpg
The reason for this is here:
http://www.lextech.org/images/needle...dlecloseon.jpg
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/needle...dlecloseon.jpg
The reason for this is here:
http://www.lextech.org/images/needle...dlecloseon.jpg
10-31-04, 01:01 AM
#6
Racer
Knocking on wood as I type this......
Incredibly, my 92's cluster has yet to experience any flicker or dead spots, and I'd like to keep this streak going as long as possible.
Might they last longer if I keep the brightness down, using the **** you mention? I'll do so if it helps, but they sure look better when brighter, both in the day and with the headlights on.
Might they last longer if I keep the brightness down, using the **** you mention? I'll do so if it helps, but they sure look better when brighter, both in the day and with the headlights on.
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