Dimmable LED bulbs for instrument clusters

[Mike Self]

Have any of y'all had good success with the LED #194 instrument cluster bulbs  that are actually dimmable?  Someone posted a couple of months ago that they used bulbs from  Super Bright Lights.com successfully, but customer reviews of those bulbs indicate that they're kinda fragile, and they don't dim properly--they go to perhaps half brightness, then go completely dark.  Only want to replace the four bulbs in the instrument cluster that provide illumination, not the warning light bulbs.

 

Suggestions or feedback from what you've used?

 

TIA

mike

[jp5Touring]

Mike I have SuperBrightLEDs in my dash and brake lights and have been very happy with them.

I did the warning lights to all but the alternator also. In dash turn signal is almost too bright at night. Installed maybe two years ago. My 2002 doesn't get driven that much at night but throw nice light and the dimmable feature works well.

 

https://www.superbrightleds.com/moreinfo/instrument-cluster-gauge/194-led-bulb-5-smd-led-tower-miniature-wedge-retrofit-car/206/919/

[calw]

No experience with 194 replacement LED's specifically, but...  The brightness curve that you mention is characteristic of LED's fed by simply varying DC voltage in general.  Your post prompted me to do the quick online search I've been meaning to get to.  I couldn't find anything that looked technically meaningful which explained the difference between dimmable and non-dimmable LED's used that way, reinforcing the gut feeling that there's really no such difference except perhaps in what series resistor(s)/LED(s) combo they choose to make the bulb (maybe biasing the LED just right puts it in the more "dimmable" portion of it's operating curve).  There were numerous techno-drivel explanations about dimmable LED's, none with actual facts.

 

There were a few references to the right way to dim LED's - feed them with a variable pulse width modulated signal instead of just varying the DC voltage (which of course wasn't on BMW's radar in the 60's).  LED's are much faster acting than incandescent bulbs, and so what you then get is a varying duty cycle of full On/Off operation.  Did I mention flicker? Yeah, watch out for flicker when you do this.  Some (many?) LED's have phosphor built in which reduces the flicker by glowing to fill in the gaps when the LED's are off.  Part of what makes the differences in color temperature that you get with different white LED's is what phosphor is chosen.

[dlmrun2002]

SuperBrightLED  is a good site for auto LED lights. I did an upgrade on my 02 rear bulbs and the result was better then I expected. I used the led color to match the lens color.  Regarding dimmable, I have them but haven't installed them yet. Hard to believe  I am changing my dash bulb color for the 3rd time. In the 80's it was green. In the 90's it was amber. Now I'm changing them to match my interior which is blue. It's amazing the dumb sh*t you get caught up with when playing with cars. At least the blues will be LED and brighter.

dlm  ny country

[dlacey]

The issue here is the dimmer rheostat I think. With 120/240V AC LED lamps the 'dimmable thing' refers to phasecut dimmer controls, which can upset driver electronics that expect nice sine wave inputs.

However, down at 12V DC the LED lamp is much simpler, with either a string of LEDs or a series resistor (or both). The issue is the LED has distinctly non-linear current vs voltage...it draws almost zero current below 2.2V and then 'turns-on' sharply with current rising very fast above 2.5V. Compare this to an old tungsten bulb with almost linear current vs voltage over the 0-12V range (and ~linear brightness)... Our instrument dimmer is just a variable resistor, with LED so there is a point where the voltage goes above 2.2V per LED and they all switch-on bright....you don't get that gradual response to voltage. What's the solution?? A current control dimmer maybe??

[Gurmail]

Mike,

 

LEDs are not filament bulbs, so they cannot dim (in the true sense of the word). Diodes can either be turned on or off. They can provide a dimmable affect, though. That affect depends on the number of LEDs in the fixture. Mosts automobile LEDs are made of SMD diodes which can emit different frequency of light depending on the type of  diode used.

 

T10 LEDs usually have one to four SMD-type LEDs which when connector to a rheostat (dimmer) can provide a dimming affect as the resistance increases and cuts off power to one or more LED. The fewer the number of LEDs with sufficient current will provide a dimmer luminance. However, there can be an LED which will flicker if the current across that LED is just sufficiently enough to turn it on - the LED will reciprocate between being on and being off.

 

I have used the different types of T10 LEDs shown in the picture (currently using the one on the right) on all the four corners of the cluster. They are designed with a refractory cover to "spread" the light. However, the way the 02 cluster is designed, the light is barely sufficient to illuminate the cluster at full power, but I can make do. I'm using red light emitting LEDs (lowest illumination). Using yellow light emitting LEDs will probably provide a higher illumination.

 

Turning the rheostat on the 02 dash (which is non-digital) will begin the dimming affect of the LEDs when turned half way down, so my lights go instantly from fully illuminating to half illuminating. I just keep them fully glowing.

 

Try looking for high luminance fixtures with higher number of LEDs which may provide better dimming affect and possibly lesser flickering.

 

Gurmail

 

[jp5Touring]

Just got a discount code from Superbrightleds.Now till the 24th get 10% off 

"F4LRAJ"   

[layers]

Hi Mike—

I installed SupertBright LED bulbs in my instrument panel a few years back and I recommend them.  They dim fine as far as I want.  Note that SuperBright controls the LED current with a simple resistor so adding the potentiometer dimmer on our cars just increases this resistance as you dim the bulbs.

 

 

I’m sure you know about the alternator charge light and I have an incandescent bulb there, as well as one for one tach position; I did not choose to remove the circuit board to install a lamp that would not fit into the 1cm-wide hole beside the tach.  Talking about the 1cm-wide hole, many of the wedge-based LED bulbs from SuperBright are wider than the 1cm diameter W5W bulb (also the American equivalent 194 bulb which is designated T-3 ¼ {tubular-shaped, 3.25 eights of an inch in diameter}) so they will not fit easily around the speedometer or tach.  SuperBright has dimensions for about all of their products if you dig down far enough so you can judge which ones are apt to fit.

 

 

Another consideration is the color of the bulbs you prefer.  While some people like the blue-white of high Correlated Color Temperature (CCT) available with LED bulbs, I prefer a more neutral CCT.  Certainly the CCT of the W5W bulb is very low and yellowish, especially when dimmed. I think the dash looks better with a whiter light between 3000 and 4000 Kelvins (K). Remember, an LED may change CCT a little when dimmed but nothing like an orange-ish dimmed incandescent bulb.  Another instrument light color promoted by BMW is a reddish-orange (probably like you have on your e30).  But even this filtered red color has somewhat more other wavelengths than a red LED bulb would have so I suggest you try a bulb you are considering if you want red in case the instruments just look too much like a red-screen black-&-white TV (think of low pressure sodium light in red rather than yellow).

 

 

Finally, you may already realize that our W5W bulb sockets have + on one SIDE of the wedge base and – on the other SIDE.  Many LED bulbs have + on one END of the base and – on the other END.  If you do not realign the LED bulb base wires so each polarity is on just one SIDE of the base, you will probably blow a fuse or two when you apply power to the new bulbs.  If you have a spare instrument panel you can try your new LED bulbs in that to verify if you like the results and find any connection glitch such as the base connections before you pull out the panels in your cars.

 

 

Have fun and see better at night!

Edited December 24, 2021 by layers
correction

[mofares]

I have had these bulbs in my cluster for years, fits snug w/ factory connector, dims w/o issues but I leave it on full brightness and not one problem. Also upgraded all of the exterior bulbs and dome/plate festoon's from this site but you'll need a LED flasher relay/connector from NAPA/Amazon if you replace the flasher bulbs.

 

194 LED Bulb - 6 SMD LED Tower - Miniature Wedge Base | Super Bright LEDs

WWW.SUPERBRIGHTLEDS.COM

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This 194 LED bulb replaces many traditional bulbs including 194, 168, and 912 bulbs. The plug-and-play bulb has a miniature wedge base and is available in cool white. It can be...

 

[Squid's 02]

I installed these LED's in my instrument cluster. I am very happy with the results. The bulbs are dimmable, but not infinitely dimmable like the originals. I am ok with that because I never really used my cluster on the lowest lighting setting anyway. 

 

https://www.amazon.com/gp/product/B07ZK7DFCZ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1