I finally couldn't take the dim dash lighting in my '86 300e. I could only see the top half of the speedometer and gas guage. This was even after installing new 3W bilbs and cleaning the light prism faces.

Using an idea I got either from this forum or from the Brickboard (can't remember which), I removed all the original plastic prisms and installed LEDs. The results are really great. Now I can see even the numbers on the trip odometer. The posted photo below shows the new lighting fairly well although the lighting is actually even better than you see in the photo. Upon examining the plastic prisms, I could see that the 'capture area' where light from the bulb enters the prism is quite small. The efficiency of this system has to be low.

If there is interest, I'll go into more detail with pictures. That is assuming I learn how to attach pictures.

Briefly, I pulled the cluster out, used a Dremel to grind out the plastic welds holding the two prism covers, removed the old yellowed prisms, painted flat white around the slots where the prisms had reflected light back to the guages, and mounted two, white, LEDs in each slot. The LEDs are powered by a 9v regulated supply which draws 12v from the dash light dimmer supply. I also painted the guage needles with a fluorescent orange model paint which I bought at a toy store. The total cost was under $5.00.

Attached Thumbnails

 

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1986 300E
1993 Volvo 940 Wagon
1984 Volvo 240 (daughter's)
1976 Dodge 1/2T pickup, gas hog

Please do, I have a burnt bulb in the cluster so I might as well go all the way in replacing it.

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1994|040|W124.036|E500
http://www.mbworld.org/forums/image....ine=1216527951

Wow...conciderable improvement....say...where do I get those new 3w 'bilbs' from ?




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[http://languageandgrammar.com/2008/01/14/youve-got-problems-not-issues/ ]

"A liberal is someone who feels they owe a great debt to their fellow man, which debt he proposes to pay off with your money."

Impressive! Please show us the pictures. Does the dimmer work with the LED's?

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Peach Parts W124.128 User Group.

80 280SL
85 300SD
87 300TD
92 300D 2.5 Turbo
92 300TE 4Matic

Hey, that looks cool but definitely not for me. I always run with my dash lights as low as I can get them and still read the gauges at a glance. Learned that trick while flying, the bright dash lights inhibit your vision outside.

You are absolutely right. I seem to remember that aircraft use red lights in their instrument panels in order to save the blue-green photo receptors in the eye for detecting lights outside the cockpit. Is this right?

I tried using red LEDs but the visibility of the guages wasn't good. Same with blue lights which were 'bloddy awful' as the Brits might say.

Most of my night driving is in the city where you get bright lights all around and the dash needs to be well lighted to compete.

As you can see in my answer to the previous post, there may be a way to include a dimmer control feature. Perhaps I'll try that although I'm a bit tired of pulling out the cluster for now.

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1986 300E
1993 Volvo 940 Wagon
1984 Volvo 240 (daughter's)
1976 Dodge 1/2T pickup, gas hog

No, the dimmer does not control the LEDs. I was satisfied with the lighting just as it is. However, if your night vision is better than mine or possibly on a long night drive (which I avoid as I get more senior), you might wan't to be able to dim the dash lights. I have thoughts on how to do this but it would require more electronics.

An LED is essentially an ON-OFF device. You can control the light a small amount by controlling the current through the LED but this isn"t really enough control. The LED output can be controlled by turning it on and off rapidly and varying the duty cycle, i.e. the time the LED is pulsed compared to the time it is off. Much like setting the idle mixture control in my MB. If this is done fast enough, the eye doesn't see any flickering of the light.

I'm still waiting to see the interest in posting the pictures showing how I did this. We'll see.

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1986 300E
1993 Volvo 940 Wagon
1984 Volvo 240 (daughter's)
1976 Dodge 1/2T pickup, gas hog

I wasn't clear enough. The improved lighting is from replacing the original 3W bulbs with an LED lighting system. The original bulbs are 3W and sometimes these get darkened with age. New bulbs help but still don't really give enough light. You can put in 5W bulbs but these are much hotter and will eventually melt or warp the plastic near the bulbs. I used LEDs because they put out practically no heat.

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1986 300E
1993 Volvo 940 Wagon
1984 Volvo 240 (daughter's)
1976 Dodge 1/2T pickup, gas hog

Turning a "milliion " times then replacing the rheostat and the bulbs with the 3Watts has NOT done it for me.

I'd be interested in the LED set up presented as a "This is for Dummies" LOL

Does running the 9 Volt LEDs at 12 Volts hurt them? What soldering was needed? Yes, please publish a procedure and sources for LEDs!

Thanks,
Spook