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2004 clk500
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Discussion Starter · #1 ·
hey i just installed some L.E.D. license plate bulbs and the light in the instrument cluster light up. thats the same light that would come up if your signal or tail lights or headlights went out. so i am guessing it must be the the l.e.d. bulbs being a so low wattage bulbs, the sensor can't even sense that they are there. so the car thinks the license plate bulbs went out so the light in the cluster pop up. is there any way to trick the sensor to make the light go off, i like to keep the l.e.d. bulbs on the car though, pics will posted soon...
 

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W203, W210 Moderator
E55 ///AMG
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mbnz230 check this thread , we were discussing that how to resovle that issue regaring the defective bulb issue.

http://www.benzworld.org/forums/w210-e-class/1263123-10-modification-you-all-can-do.html

1. Get a pair of 6-LED festoon bulb from ebay. ($8)-size between 36mm to 41mm (I got them from "US HOME DIRECT", I am at east coast and take less than 3 days to get to me)
2. Get a 100 ohm 10W resistor from Radioshack ($2)
(sole purpose is to "fool" your car thinking the license bulb still working)

Step 1, replace your license plate festoon w/ LED Festoon.
Step 2, Parallel connect, ONE of the resistor to the Positive and negavie wire of your festoon socket.

(remember, all you need is ONE resistor for both side, because they are in-line current)

********* they are actually brighter than the picture I provided, (it is rainning) and NO MORE "DEFECTIVE LAMP" warning on your cluster **************
Attached Thumbnails
 

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2004 clk500
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Discussion Starter · #3 ·
right on...

this is exactly what i was talking about... thanks alot for this information, i coulda never figure out how to trick the system. will try that out and hopefully cure my problem. i am pretty sure it will... i will keep you posted.
 

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Premium Member
SL55, 300SE, GL450, Daytona 955i
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If 100 ohm resistor was good for the gob, I would suggest using two 200 ohm resistors, one on each bulb, and have them soldered to the bulb ends. This will better dissipate the heat and maintain the symmitricality of the devices in the car.
 

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S600, ML55
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All you wan't is simulating the bulb with a load resistor

Actually the computer is looking for a certain current drain produced by the bulbs running when you bturn the light switch on. The current is generated by all lamps.
A particular lamp has a wattage usually printed on the metal socket of the bulb or as indicated in the user manual. If you replace a normal bulb with an LED bulb you have way less current running than the computer likes to see. As an Alarm to indicate a defective Bulb, he turns the light in the instrument cluster on. You can not just put a 100 or 200 ohm resistor in paralell with the new LED bulb. You have to calculate the resistor based on the Wattage of the original bulb. If you have a 5 watt bulb that you like to replace, calculate the following
The Battery Voltage of the W140 is nominal 13 volts with running engine.

The calculation is as follows R = E 2 / P
Where R is the Resistor
E is the Voltage
and P is the Power in watts
Use the on line calculator here http://www.the12volt.com/ohm/page2.asp to calculate the resistor In our case is 33 ohms and 5 watt for a 5 watt bulb.

You can do this calculation for any bulb that you like to replace with a LED bulb.
Now the computer does tolerate some variation due to variation of the Battery voltage and the fact that you have a little load coming from the LED. You could round the resistor value up by 20 to 25%, because resistors are only awailable with certain values. So select the one close to the value you need, but never smaller..rather bigger that you actually calculated.
 

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1999 S600 W140 and 2002 S55 AMG W220, (previous: 1989 560SEL and 1995 / 1996 S500)
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mbnz230 said:
while i am at it i took a pic of my superwhite headlights as well.
whoa mbnz, those look great. Those headlights look beautiful too. Beautiful Mercedes-Benz. :)
 

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I assumed the calculations were done when they gave the 100ohm value.

if we use the basic ohm law

V=R x A

and power equation:

W=V x A

at 13V, a 5 watt bulb will have a 0.38A current and hence 33.8ohm resistance.

now to fool the computer, we need to hook a combination of LED bulb and resistor to have a total overall resitance of 33.8 per bulb (aka per side).

the LED bulb has higher resistance than regular light bulb, so a resistor should be hooked in parallel to drop the overall resistance to 33.8ohm (or close by.)

depending on the resistance of the LED light bulb, the value of the resistor for each bulb should be calculated as follows:

(1/Rled) + (1/Rradio shack) = 1/33.8
 

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1995 S420
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Damn MBNZ, what type and brand of headlamp are you using? Or is the white from the white balance of the digital camera? If it is a halogen bulb, I'd love to know.
 

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Calculations

Yes, is all correct, but there is one more equation

You simply divide the resistor value by the Lumen output of the bulb and the result equals your age!!!

By the way joke aside.
For the internal lights and the cluster lights you don't need to worry about a resistor. Just replace with LED's. The Computer does not control the internals. by the way, there is a lot that could be done with internal LED Bulbs. Just think about it
 

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2004 clk500
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Discussion Starter · #13 ·
headlights

ychachad said:
Damn MBNZ, what type and brand of headlamp are you using? Or is the white from the white balance of the digital camera? If it is a halogen bulb, I'd love to know.
the headlights are halogen bulbs, i got them off ebay along time ago, i got a couple sets left, they are fairly cheap. But i have been very happy with the performance of this brand, its hiper or something, i got some bulbs left in storage i just dont know the brand on top of my head. i got some extra just in case one goes out, but this set i have been using for over a yr now. i have not adjust the balance or contrast thing on the camera, its not touch up or anything, i just shrunk the image thats all.
 

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Goatman said:
Yes, is all correct, but there is one more equation

You simply divide the resistor value by the Lumen output of the bulb and the result equals your age!!!

By the way joke aside.
For the internal lights and the cluster lights you don't need to worry about a resistor. Just replace with LED's. The Computer does not control the internals. by the way, there is a lot that could be done with internal LED Bulbs. Just think about it

Hahaha...

That use to be a common joke back in high school:

A train running at 60MPH, with velocity of 200000LBS, if the gas price is $2.60 per gallon, calculate the age of the driver.

You are absolutely correct about the interior lights; however, the problem with LED lights is they are not dissipated as regular light bulb is, if you know what i mean.

Like if you install two for the dome lights, the color will look really cool, but they are going to make two bright spots at the center console, and barely get any light at the internal door pockets.
 

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1993 300SEL (Sold) 2007 X5
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bayhas said:
Hahaha...

That use to be a common joke back in high school:

A train running at 60MPH, with velocity of 200000LBS, if the gas price is $2.60 per gallon, calculate the age of the driver.

You are absolutely correct about the interior lights; however, the problem with LED lights is they are not dissipated as regular light bulb is, if you know what i mean.

Like if you install two for the dome lights, the color will look really cool, but they are going to make two bright spots at the center console, and barely get any light at the internal door pockets.
Are you saying that they are in series and will not allow power to the other bulbs?
 

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SL55, 300SE, GL450, Daytona 955i
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No no...I mean the light reflection from the bulb... the light emmited from the dome light will be consentrated in one round spot underneath the bulb, at the center console probably...
 

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1993 300SEL (Sold) 2007 X5
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bayhas said:
No no...I mean the light reflection from the bulb... the light emmited from the dome light will be consentrated in one round spot underneath the bulb, at the center console probably...
I kinda want to put the lights in but still want light to see things in the cabin because the stock ones give very good light as there are a heap of them.
 

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2004 clk500
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Discussion Starter · #18 ·
need to get the resistors tonight.

so should i use 33 ohms and 5 watt one on each side or 100 ohm & 10w or 200 ohm 10w one on each side... seems to me everyones got a different conclusion.
 

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Discussion Starter · #20 · (Edited)
not yet...

i still havn't purchased the resistors yet, the lights work but the light in the cluster is still on... i just did some calculation on http://www.the12volt.com/ohm/page2.asp for a 12 volt car battery and 5 watt bulb the resistance is about 28.8 ohms... so should i just buy two 28.8 ohms 5w resistor?
 
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