Instrument lights - 2W or 5W???

[homerj40]

I have pulled all the gauges, clock, radio etc. for repair and refurbish on my 66 250 SE Coupe. The lighting was always a bit dim with the original 2W lamps installed - Has anybody switched to 5Watt bulbs in the instruments??? I am curious if that might generate TOO MUCH HEAT???

Thanks for any advice/comment/experience that you might have,
Darren

[Tyler S]

Others have added 5 watt bulbs. However there is the question of what the added heat will do to the instruments and also may cause overload/damage to the NLA dimmer switch. You can safely replace the 2 watt bulbs with 5 watt equivalent LED's for more light. Use the search above for threads about LED replacements.

[wwheeler]

I am using 4W bulbs now in my W111. The lightning is perfect with that I think. I really don't think you need more than 4W. Yes, heat is a concern but I rarely drive my car at night.

When I redid the dash, I decided to use incandescent for the gauges and clock lights and LED for the rest. The reason was I could not find an LED bulb that would fit the clock (different than the W113) and the tach which is electric, not mechanical . Then the gauge lighting would be inconsistent. The turn signal and middle cluster lights are LED (except for generator light and low fuel).

I also use LED for the inside cabin lights. That makes a huge difference.     

[rgafitanu@gmail.com]

I used 5W bulbs, 2+2 in the tacho and speedo and one in the central piece and it discombobulated the dimmer. It started smoking and loosing contact. I had to short out the dimmer in the connector. In hind sight I should have used 4W or LED. I think that my problem was caused by the fact that earlier I replaced my defective dimmer with a sedan dimmer. It has fewer bulbs so it's lighter power load. Instrument removal is such a PITA that I will wait to fix this until bigger problems will make me take it apart.

[mmizesko]

I would go with the LED solution. I drive at night a bunch, and love the added brightness with no heat.  Good threads on this site if you search LED.

Mike Mizesko

[wwheeler]

The problem as I remember on the W111 is the clock and the electronic tach. For those two, the LED bulbs at that time had too big of a head to fit inside the opening. Only incandescent bulbs would work just like the low fuel bulb on both W113 and W111 center clusters.

Note that the earlier W111 (and I believe all W113) may have the mechanical tach and the LED may work. I do not know about that. The clock is different on the W111 than the W113.   

[homerj40]

Yes, I bought a set of LED bulbs but they have this plastic ring that won't fit into the Speedo/Tach housing, etc..

After checking the other posts on LED lighting I see that OSRAM makes 4W LED bulbs that will fit, YAY!

I will post a follow up once I get the gauges back and have installed everything.

Thanks for all the input,
Darren

[wwheeler]

Can you post your link to the LED Osram bulbs? I was careful to say "back when" I did the dash restore, they didn't have the LED bulbs. LED bulbs are changing at a dizzying rate and so nothing is the same from day to day.

BTW, if you like the incandescent color of light, you will need to get a soft white color (lowest Kelvin temp). The other colors (High Kelvin) are far too white/blue.

Thanks. 

[homerj40]

Can you post your link to the LED Osram bulbs? I was careful to say "back when" I did the dash restore, they didn't have the LED bulbs. LED bulbs are changing at a dizzying rate and so nothing is the same from day to day.

BTW, if you like the incandescent color of light, you will need to get a soft white color (lowest Kelvin temp). The other colors (High Kelvin) are far too white/blue.

Thanks.

These two threads had the best info I could find.

https://www.sl113.org/forums/index.php?topic=19084.0
https://www.sl113.org/forums/index.php?topic=22957.msg164215#msg164215

I ended up finding the best deal for the bulbs on eBay. They say "Warm White" but indicate 4000K so we'll see how they look. I'm not too concerned about originality, I'd rather have a more visible display. Plus, they are dimmable:

http://www.ebay.com/itm/301614249206?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

I went with all the same type - 1LED/90 degree bulb - for simplicity and uniformity.

REMEMBER: the Alternator and Low Fuel lamps MUST remain 2W incandescent to function properly

[wwheeler]

4000K isn't warm white and that is the same Kelvin as a standard cool white fluorescent tube. So it will be more blue and white. That is the nice thing about the Kelvin ratings. It is what it is. No funny nominal names. To duplicate and incandescent bulb, you need 2700K. 3000K is also good and about what most halogen lights are.

As far as brightness or lumens, it looks like this LED has 50 lm which I would assume is lumens. To compare to incandescent, 2W is 11 lumens and 4W is 38 lumens. So this bulb should have slightly more light than a 4W incandescent bulb. I like the lights and wonder if you can find them in 3000K?

The comment about the bulbs needing to stay incandescent should only apply to the generator light. That is because the circuit needs the resistance of the incandescent to function. The low fuel circuit should not matter. The reason on that was simply the need for a LED the same diameter of the metal base. The ones you found should work.

If these are as bright as they say, it may be too much for the indicator lights in the center cluster. One other note, LED lights look best when their color matches that of the lens. IE., red lens, red LED.

[wwheeler]

I bought two of the LED OSRAM 3850WW-02B and installed in my W111 electronic tach. Until these bulbs, only a incandescent BA9 bulb would fit. The lumens are good and provides lots of uniform light. No hot spots and actually more uniform than the incandescents. It is a bit like the color of warm white Christmas lights I see that aren't really warm but kind of a yellow cool white.

Still with no worry of overheating, these are the best I have found so far. This bulb will fit all of the fixtures and the dash will have a bright uniform color from now on. I just ordered 5 more to fit on the others. They only seem to be available in Europe. Hopefully the last time I will have to worry about this.

NOTE: The plastic LED lens was just a tiny bit too big in diameter (.005"?) to fit in the tach bulb holder. I was able to file off just enough of plastic so that it went in. Just a minor annoyance.

Thanks to Darren for pointing them out.