W123 Painted Cluster needles and Retrofitted LED's
 

Needles used Testors Tangerine Orange and Testors Paint thinner 3:1 ratio. The paint thinner helps avoid brush marks caused by the thick paint.

https://i.imgur.com/Sk10aMn.jpg?1https://i.imgur.com/HFjYclh.jpg
From left to right:
1)Blue- High Beam
2)Red - Battery
3)Amber - Brake pad wear sensors
4)Red - Parking Brake

Not shown:
5) Amber - Seat belt
6) Amber - Glow Plugs

The prism / fiber optics are both Amber. Also replaced the turn signals, Octopus, and Hazard light switch with Leds.

The cluster small bulb 74's are a ***** because the original bulbs are soldered onto the plastic twist off cap. Had to solder my own wire to the new LED's and solder them to the metal connections that hold the plastic cap to the cluster board.

https://i.imgur.com/lvm6fio.jpg
https://d114hh0cykhyb0.cloudfront.ne...wedge-base.jpg


If anyone has a spare cluster plastic lens/cover, and or the indicator icons...shoot me a PM.

Looks great.

One thing though. You will have to keep the 3 W incandescent bulb in the battery light. It needs this for the alternator to charge properly. The electrical characteristics of LEDs are incompatible with the voltage regulator.

Jaybob, could not a regulator of sorts fix this?

Can anyone tell me what the benefit to putting LEDs in idiot lights is?

No.

I am not sure if LED bulbs give off more or less heat. If more heat, there may be a concern with distorting the indicator icon films.

Has anyone been able to find out which is the best product among those listed here?
https://11must.com/best-clamp-meters/

Thanks,

Could you elaborate for sake of my own ignorance? How does a 3w bulb allow the alternator to charge? (My car is a 1983 300D turbo , if that changes anything)

I will look into this. Thank you for the warning

The 3w bulb provides resistance which is needed to allow the alternator to charge. Mercedes automobiles are very sensitive concerning the wattage of bulbs used in the tail and stop lights also. Not using the correct wattage bulb will disable the cruise control.

Spare Binnacle Lens
 

Your gauge needles look great ! .

When asking for parts, always give your location, you'll be pleased by the response from folks you didn't even know lived near you that have parts.....

Pardon me, my electrical engineering know-how is next to nothing.

I meant, couldn't we add a resistor post LED to create the same effect?

Edit: love the safety hat orange too OP!

Not doubting you as the German engineers are not all that adept in regards to how electricity works in fact, they treat it as though it has some "mystical" properties beyond mere human comprehension, but I am questioning whether the use of a front/rear/tail light marker LED bulb would have any effect on the cruise control.

I can see the stop/brake light bulb having an effect but the marker/tail?

I don't think the lighting circuit is involved with the cruise since it can be engaged without the lights but I've been wrong many times before.

Thank you and for the tip

I mis-spoke. . The stop light bulb resistance is the bulb that will have an effect on the cruise control, not the tail light bulbs. This issue has been discussed many times on this forum. Refer to posts by James Dean, the forum cruise control expert.

Only LED brake lights will affect the cruise control, I found this out the hard way and with help from the forum here. The tail lights, reverse lights and blinkers will not affect it (although the blinkers need resistors to blink correctly).


To the OP - I would take a night drive to see how bright the new LED bright light indicator is. I had to put the original incandescent bulb back in because it lit up half my car.

@JayBob

Is the recharging ability of the alternator affected because of LED polarity or something else?

The LED on my Battery light is non-polar, just like the 74 bulbs.

Only able to find 3-4 threads from him. Non bulb related.

EDIT: The correct username is JamesDean , no space.

Thanks for the clarification.

To anyone who questions my concerns regarding German electrical engineering, I advise them to take a quick gander at the wiring schematics of the W123 ACC system.:eek:

The alternator light serves as a ballast resistor to "flash" the alternator to make it produce voltage. It has to pass a fair amount of current which is why it takes a 3W bulb. The glowing is a secondary function to its main purpose of being a ballast resistor. Don't bother reinventing the wheel here, stick with the incandescent bulb. It is also there to alert you when the alternator stops charging. It is never fully "switched off", so an LED may continue to glow even if the alternator is charging.

Wiring and electronics are not the Germans' forté. They seem obsessed with bunching things together and mixing in positive and negative switching on a variety of circuits. No schematic is ever drawn the same way twice either.

If you ever want a truly face-palming design, look no further than the seatbelt warning relay on a Gen II W126. Whoever designed that circuit was probably a vegan chef or something and happened to pick up a "DIY" type book on electronics and thought they could handle it. They sure weren't familiar with electric circuitry or common sense.

:2thumbsup

Just tested my battery with car off and it sits at 12.85v.

Tested the battery cables with engine at idle for 1 minute and its charging at 14.25v. It seems as my alternator is working properly?

If it matters; the LED's have been in the car for 48 hours. I have driven around my small city for about 20-30 minutes twice in that time. And took a 25 mile trip to the park, car sat for 4 hours, and 25miles back. Lights on, radio on, etc.

The alternator has the ability to self-flash when the RPM comes up on the engine. In cold/wet weather or when the alternator gets tired (or if you try to jump a dead battery) that alternator light becomes far more important. It's your car, you do what you want. I'd leave the incandescent there to do the purpose it was designed for.

Nor with air-conditioning. A result of building and originally selling cars mostly in a relatively temperate zone where most cars didn't even have AC. Unlike US manufacturers whose customers have to deal with the swamps of LA, the sub-tropics of FL and Death Valley CA.

Genuinely curious as to what the motivation is here because I still have yet to see a good reason to put LEDs in idiot warning lights mentioned at all. There are numerous benefits to using LEDs in other applications in the car, but none for this use that I can tell - only downsides.

Hoping someone can explain.

I agree. I am unable to see any advantage in installing LED lights in the dash. The stock lights are bright enough for me and I am 71 years old with not the best vision. Everyone to their own taste!

Behind the color filter they might even be less bright. All while adding multiple potential failure points per bulb at increased cost compared to an incandescent bulb that typically lasts 40 or 50 years or more.

The benefit? It’s a project. My car doesn’t have indicator icons so I wanted to color-code the different bulbs. LEDs also draw less from the the battery.

And every and any type of bulb is a potential failure point. I’ve found several burnt out incandescent bulbs. Incandescent’s also Product more heat. Even the proper wattage bulbs can cause melting when burning out/dying.

You can also change the color of your interior lighting.

Not a project for the faint of heart, but a goal and achievement non the less.

Reduced heat and current draw aren't perceivable benefits when the light is only applied for the short time in between key insertion and engine start. Running lights are a different story.

Every bulb is failure point. An incandescent has one: the filament. You've just added about 10 more per bulb with the solder joints and numerous electronic components.

That said, doing it because you want to is a fair reason.

LED's
 

I think it's a worthwhile job .

To each their own .

I spend inordinate hours taking things apart, cleaning, lubricating, adjusting and re assembling them just because I enjoy it and I have older high mileage vehicles so I like everything to work "Just So " :rolleyes: .

No downside to LED bulbs unless you're afraid of them .

I run LED's in my backup and running lamps and the front turn signals ~ this way I have brighter rear turn signals and the factory transistorized flasher still works .

Once the alternator's drive belts and wiring etc. are fine, the charging voltage depends mainly on the brand of voltage regulator ~ I only use BOSCH and so get 14 VDC when they battery is low and 13 VDC when it's fully changed ~ those off brand regulators rarely reach 13 VDC no matter what .

In the W201 I've modded the turn signal flasher relay for use with LEDs and run incandescent bulbs in parallel with the brake lamps to maintain function of the cruise control. In another car I had to run an incandescent bulb in parallel with the brake lights to maintain function of the ABS when using LEDs. The instant-on illumination of the brake lights can be considered a safety feature, and in the running lamps it lessens load. In turn signals it's for no real other reason than it looks cute, so by no means am I against using LEDs. But to say there are no downsides is simply untrue. They're failure prone, and it's not usually the diode that will fail it's something else before it.

As an old person who's been working on vehicles for over 50 years I can tell you LED's fail just as incandescent bulbs do, what other down side is there ? .

The only place I ever put LEDs in my 300D were the two that light up the cluster at night. It might have been because of a problem with the rheostat, but the old incandescents just didn't have enough same candle power.

It was a recommendation by Chad300DT. I must say, it was the best mod that I ever did.

My ultimate goal was the use clear glow in the dark nail polish on the cluster and then put in a blacklight LED to make it all glow. I never did it mostly because of my painting inabilities.

Now that would have looked cool!

Well cost for one, and also all the stuff required to get them to work in systems designed around incandescent bulbs as has been touched upon already in this thread is another. Want an LED in the W126/124/201 reading light? The socket is wired in reverse polarity. Have to disassemble the LED and resolder the leads. Whether the cost and effort is worth it is up to the user, but the incandescents do the job just fine cheaper with no thought involved.



Many unrestored cars from the '50s on up have original bulbs in the idiot lights. I highly doubt the current slew of Chinese LED bulbs will last that long.

Hey would you mind posting a picture of the paint you used? I know you mentioned the brand and color but I'm seeing a few results when I Google "Testors Tangerine Orange."

Your needles came out excellent and just the right color. I've seen many people use the wrong color and I'd like for mine to look exactly like yours. Thanks

- Sonny

I can send it to you. PM me

Alternator Charging
 

The 3W bulb for the battery idiot light provides DC excitation (12V is provided to the alternator's field windings - this excites, or "jump-starts" the alternator). Without it, the alternator will not charge.

I changed the two instrument lighting bulbs on mine to LED's but didn't go any further. I like it. The light is "whiter" and the bulbs work with the rheostat. The paint was Testors Fluorescent Red. It all works. I also got mad at Mercedes for making the combo gauge all metric on a U.S. ONLY car so I got one of their earlier gauges in SAE, removed the decorative silver center button and stuck a black disc in its place to match the rest of the gauges. Sorry but between a reading of 2 bar vs 30 psi, 2 bar sucks.

Thanks, Wusha, for sending me the supplies to repaint my needles.

Before:

https://i.imgur.com/aabkcXLl.jpg

After:
https://i.imgur.com/y6zlInZl.jpg


For the record anyone researching about painting their needles, Testors "Gloss Tangerine" is the way to go for older Mercedes. Make sure to thin it a bit as not to leave brush strokes.

Also, save yourself the extra step and extra product there is no need to thin. That's not how this or any ready to use paint works.

FOund this on a different car forum, Not a merc, but looks like it might be a solution... The wiring colors are incorrect so dont go by them.

"
Start with the "normal" warning lamp configuration where a white wire goes from the ignition switch, to the lamp, out the lamp via a brown/yellow wire and finally off to the alternator. Replace the warning lamp with a 40 Ohm power resistor (something rated for at least 1 Watt). NOW get your LED lamp assembly. A plain LED will need a "dropping resistor", typically 1000 Ohms. A pre-configured LED warning lamp will already have this resistor inside. Take your LED lamp (or LED with dropping resistor) and wire it in PARALLEL with the 40 Ohm power resistor. Pay attention to the polarity or the LED will not light. With the LED wired in parallel to the 40 Watt resistor... the LED will turn on and off just like a normal incandescent light. However, the current required to power the alternator field coils on startup will pass through the 40 Watt resistor."

Anyways, I'm attempting this myself, I'll report if I have any luck.