Has anyone converted their instrument panel illumination lights to LEDs yet? They are being sold as upgrades and are supposed to make the instruments brighter (good for these older eyes). I know the 2 watt bulbs can be replaced with 4 watt bulbs, but I was warned by North Hollywood Speedometer not to do it as the extra heat generated will eventually fry the innards of your instrument. I like the idea of brighter instruments however.

yeah, some member's kid was doing it for extra pocket change.....

LEDs are the way to go IMHO, but I lost the link for the replacements.

Oh and if you wanted to use them for the generator light, you'd have to match the wattage that the bulb was, in other words i think it's a 4watt bulb, so you'd have to use a LED+resistor combo to get 4watts.

Umm - isn't the whole point of the LED is that it gives off no heat at all?

Some of the guys on the smart car forum tried them. No problem with heat but they did find that the light was quite focused - not nicely spread out.

They are cheap - have a go and see what happens.

I hear the top of the tach is a little dark.. Dr. Evil modded a tach with a third bulb spot to help with that. I intend to do the same.. eventually.. guages are the least of my worries right now.

this is true....

the light is pretty focused.....

but i believe the kid's site had pictures and the guage was very nicely and evenly lit....

QUOTE (swl @ Aug 24 2005, 07:56 PM)

Umm - isn't the whole point of the LED is that it gives off no heat at all?

yup...unless you apply 12V to a LED without a resistor....

after the explosion and subsequently burning my fingers, I looked and the platic covering blew up...

I bought a set of white and red LEDs for the cluster of the 914. I also saw some other member with blue.

I honestly don't think they are worth it, the light they push is not rich enough for the gauges, you can barely see the gas gauge with the LED. Note that I had very good original bulbs allready in the car.

In order from better to worse, White, Blue and Red.

New original bulbs will bring back a good lighting.

In any case if you want to buy some go here instead of eBay, it will be pretty cheap.

Yup, all blue. I did mod my gauge with a third bung in the center of the top of the tach. 100% worth it. The LEDS are just fine, but if you go colored you should relize that certain colors will not show well with some of your gauges features like the needles. I recommend painting your needles white like I did. They reflect just fine, now. Do a search and you will see my gauge pod. Try looking under thired tach light or something.

NH speedo did mine. I am VERY happy with the results! I can actually read what my instruments say at night time!

Looks a lot better in person than in this picture.

Wow. That does look easy to see. What does something like that cost?

Bought mine from Qarl a year ago- the blue ones. They are not nearly as bright as the ones shown. The ~B~L~U~E~ does look really bling-y, but it doesn't read easily in my old eyes. The color makes the shapes look fuzzy (no i am not on drugs). I really think good correct bulbs will be brightest, or at least bright enough. I may change mine back. If I do I'll sell you my blue leds- Qarl sold em really cheap- I dunno, $1.50 ea or such.... Guess I'd go $1.00 per led.

I'll bet that NH Speedo setup has quite a few LEDs in there. A lot more than 2, anyway. LEDs don't put out a lot of light compared to incandescents, and they only put out light in a narrow beam, not spherically. They use so little power and emit so little heat, however, that you can use a dozen of them in place of one bulb and end up with more light for less power. You need to rig up a little board with them mounted so they point in several directions to get a good spread of light.

LEDs also can't be dimmed using the normal means of just reducing the voltage, so you're dash light dimmer won't work. LEDs are either on or off. "Dimming" them involves flashing them fast enough you can't quite see the flashing. The duty cycle of the flashing will determine how bright it is. This doesn't take much circuitry to accomplish, but it's more than a simple rheostat and a bulb.

The eye does not respond well to blue light, and things lit with that appear fuzzy to just about everyone. Green is a much better color to light something with, but green LEDs are quite a bit dimmer than blue leds. If you use an array of blue, red, and green LEDs, you end up with nearly white light (tends to be blue-shifted, since the blue LEDs are so bright). Amber LEDs also work pretty well for lighting.

The best way to get your gauges glowing... go with LEDs, then take apart your gauges and polish the metal inside. Makes them much brighter. My speedo and tach look way bright compared to my left-side combo gauge which I have yet to re-do...

No one has brought up case mods yet. You can get EL lighting in tape and rope, and the inverters used to drive them usually take 12V in.

EL lights

QUOTE (lapuwali @ Aug 25 2005, 07:45 PM)

The eye does not respond well to blue light, and things lit with that appear fuzzy to just about everyone. Green is a much better color to light something with, but green LEDs are quite a bit dimmer than blue leds. If you use an array of blue, red, and green LEDs, you end up with nearly white light (tends to be blue-shifted, since the blue LEDs are so bright). Amber LEDs also work pretty well for lighting.

The new breed of GaN LEDs can produce a very bright green, much brighter in apparent brightness than the blues (also GaN technology). You can also find teal and shades of aqua, etc. They even have purple now (horrible visibility though).

The issue of apparent brightness vs. color is definitely a concern but you can find LEDs in any color that are more than bright enough for the purpose - the problem is spreading the light out like has been mentioned.

I think there are companies that are making side emitting LEDs now. Maybe those would be worth a shot?

Fuzzy? Hard to read? My picture makes them look like crap compared to reality.

You can BARELY see the light during the day, but then again you don't need them in the day. You don't need them too bright at night because, um, isn't it usually dark out at night anyways!?

If you want the best brightness and readability, just go with white LEDs. I chose blue because it's my favorite color...trying to keep thing simple and fun!

NH Speedo has some good pictures on their site of the upgrade. Here's a good one comparing the new LEDs with the old style: http://www.nhspeedometer.com/911/custom_co...ng/911dark1.jpg

QUOTE (mrihop @ Aug 25 2005, 09:39 PM)

NH Speedo has some good pictures on their site of the upgrade. Here's a good one comparing the new LEDs with the old style: http://www.nhspeedometer.com/911/custom_co...ng/911dark1.jpg

Wow, that's amazing looking!
I wonder if they paint the inside of the housing white or polish them. I have a while set of stock 2watt bulbs so I'll just go the painted route. I seem to remember someone painting the housing flat white (not sure, but there was some reason he went flat white instead of polished etc). All these ideas etc are great!

I stuck with the stock bulbs when my gauges were at NH Speedo for other work, and I remember that their quote for LEDs was not cheap, but they did say that they were still dimmable. It appears that they do more stuff than replace the bulbs, because their results look different than just the LED replacement bulbs.

I may switch to LEDs when the speedo gets recalibrated for the 16" fuchs and taller tires that will go on after the GT flares....

Eric

who said they weren't dimmable????

i've played with LEDs for years....there as dimmable as a regular bulb.

QUOTE (bd1308 @ Aug 26 2005, 10:58 AM)

who said they weren't dimmable???? i've played with LEDs for years....there as dimmable as a regular bulb.

They are indeed dimmable.. but say your LED needs 3 volts for full brightness.. half brightness will not be 1.5 volts, but something more like 2.8. So once you add the resistor to the LED so it gets 3 volts from the 13.8v system, you need to be able to drop that voltage to something like 12.5 volts. Now your stock variable reststor for the instrument lights is probably 10 ohms or so.. When compared to the resistor needed to give the LED 3 volts at 13.8, that's nothing. All this gets thrown out the window if the LED modules have an internal regulator (which they might). If that's the case they will be the same brightness from 15v all the way down to something like 3.2v, because the regulator will vary its resistance to keep the voltage to the LED itself at 3v.

QUOTE (bd1308 @ Aug 26 2005, 09:58 AM)

who said they weren't dimmable???? i've played with LEDs for years....there as dimmable as a regular bulb.

I did.

Here's an example of why, and a dimmer that works, but isn't just a pot:

Dimming LEDs

It may well be that NH Speedo provides a circuit board for the inside of the gauge with several LEDs, a voltage regulator, a transistor, and a handful of resistors, as shown here. They could also be using a simple timer to produce dimming via PWM. None of this is all that expensive, but it's more than just a bulb, a wire, and a pot.

If I were doing this I would dim them with PWM in response to the voltage change across a voltage divider formed by the dimmer knob and a dropping resistor. The downside is you would need a custom circuit to connect all the LEDs to and you wouldn't be able to use them as a drop in for regular light bulbs. (Unless you included a tiny dc-dc converter and the pwm circuit inside the base of each bulb.)