Dashboard Switch Lights LED Conversion DIY...

Post by **DWeisbrod** » 06 Jan 2011, 20:05

I'm not sure if anyone else has ever done this, I did a search and didn't see anything, but I can't imagine I'm the first. But maybe I'll be the first to document it?

Anyway, I don't post too much around here, but I love this site, and have found it to be a great place to come when I'm stumped. Maybe I can pay it back a little bit with this? Being an artist and tinkerer instead of an engineer definitely puts me at a disadvantage, but I do my best...

Anyway, I got tired of the lights on the switches along the dash always burning out... It seems like I replace them every couple of years, and I'm hoping that LEDs will last... Plus, since I do a fair amount of SCCA Road Rallies, I thought I might like a red color better for my night vision. So I start investigating how I could put LEDs into the stock lamp sockets of the switches.

First, a little research, both online and with a multimeter. Figured out that all I needed was a 480 ohm resistor and I would be able to keep from blowing up my LEDs. Now, how to fit them inside the socket without modifying the switch casing itself?

The answer is explained below:

This is the stock lamp inside it's housing:

So what I needed to do was make some kind of assembly with a resistor and LED in it that would fit into the lamp's housing. So I soldered a small 480 ohm resistor righ up underneath the LED. Here it is next to the old lamp:

When I took the lamp out of the housing to figure out how to fit this inside, I realized that I wouldn't be able to fit it inside the housing, because the housing wasn't completely hollow: It has two holes - one for each lead of the lamp.

So I resorted to more extreme methods: I took a jewelry saw and cut the lamp housing off right above the clips:

After cutting the housing, I fed the leads through the old lamp housing:

Then I wrapped the leads around the flange of the lamp housing, trimming the length so that they would fit easily in the channels, just like the original lamp leads did:

The final assembly, which plugs right into the back of the switches just like the original lamps (although you really have to squish down the leads close to the flange, or else they go on REALLY hard, and it is easy to strip the slot on the back of the housing...

After making the first one, I got a lot faster - I can make one every 2-3 minutes now. So I started an assembly line, and replaced all the lamps in all the switches along the dash. No more fumbling for my TRACS button, or for the fog lights because the stupid bulbs have burnt out again... And now the red is much better on my night vision during Rallies...

Anyway, just thought you all might like to know how easy it would be to put an LED in those switches...

Maybe I'll post pics of my homemade 75-lb, 10-gauge skid plate sometime soon.

Anyway, thanks to everyone who contributes a lot on this site - what a great wealth of information!

Dave

Post by **thecheat** » 06 Jan 2011, 20:55

This is a great how-to!

PS: Can you tell me if the parking light position on the headlight switch is lit? Mine isn't and it seems like it should be.

Post by **Ozark Lee** » 06 Jan 2011, 21:04

Thank You Dave,

I am pinning this one in the repair database. How did you figure out the polarity when socketing the LEDS? Was it just trial and error since the sockets will work either way?

...Lee

Post by **DWeisbrod** » 07 Jan 2011, 05:46

Lee,

I figured out the polarity by using my multimeter. When measuring the voltage off of the switch housing, if I have the leads reversed on my multimeter, it shows a negative sign. So that was easy enough. Then you just need to take into account the fact that you are turning the lamp housing clockwise to tighten it, and the line it up right. I did it wrong once or twice, and it was easy to just pull the housing back out and then rotating it 180 degrees. If the LED doesn't light up and you know you've got it all tight, then you've got it wrong!

Thanks,

Dave

Post by **DWeisbrod** » 07 Jan 2011, 05:53

thecheat wrote:This is a great how-to!

PS: Can you tell me if the parking light position on the headlight switch is lit? Mine isn't and it seems like it should be.

Thanks!

And yes, you should have a light at the parking light position. I made mine red, and the kept the green for the "Always On" position. I'll replace that green bulb with a green LED this weekend. Just to complete the conversion!

When I get home tonight, I'll take a couple more pictures and post them - of the switch housings with the new LEDs in them, and then maybe one of the dash at night when it's all lit up.

And maybe I'll also post pics of my rally-light switch (a stock rear-fog light switch) with the full-color LED in it, so that it's green when the lights aren't armed, and amber when they are armed. (I switch off the ground to the relay, and run power to the relay through the high-beam switch, so my floods and my high-beams all go on at once, when the relay is armed!)

Thanks again,

Dave

Post by **thecheat** » 07 Jan 2011, 07:23

That is awesome, thanks! You should come up with a guide on converting the $7 each instrument cluster bulbs to LED... but I'm not sure how well the limited light angle of the LEDs would work.

PS, how does the dimmer switch work? I assume at a certain position they just stop lighting up, right? I leave mine on full brightness anyhow.

zhenya · Post by **zhenya** » 07 Jan 2011, 12:37

Dave - somewhat off-topic, but will you be at the FLR Winter Rally tomorrow? I'll be there in my 855.

Post by **BEJinFbk** » 07 Jan 2011, 12:59

You can find many of the LED's already built at www.autolumination.com.
Look for the neo wedges for the shorties. The tall ones may be a problem...

Post by **DWeisbrod** » 07 Jan 2011, 17:42

zhenya wrote:Dave - somewhat off-topic, but will you be at the FLR Winter Rally tomorrow? I'll be there in my 855.

Zhenya,

I will not be there, unfortunately. I hope that it is the only one I cannot make this season! I am an advisor for my school's FIRST Robotics team, and tomorrow is our big kickoff for build season. But I will look for you next week: It's unusual to see Volvos at those events, My friend John and I are usually the only ones who run Volvos (I with my 854, and he runs a 964). There was a green 854 there last year, but I only saw him at one event that I can remember.

Maybe I'll see you in 2 weeks!

Dave

zhenya · Post by **zhenya** » 07 Jan 2011, 20:39

Too bad - it would have been fun to see another 850 there! This will be my first rally in quite some time - I've done a couple of small ones with my dad and the Porsche club over the years, but nothing at all like this. My own job keeps me out of town a lot, so hopefully I will be able to meet you at another event later in the season. (and if my navigator will come back for more, that is!)