DarkFox118

iTrader: (7)

So, I'm going to slowly transition my car's interior lights over to LEDs.

I started when I broke my tiny size 74 incandescent bulb in the center console trying to swap center consoles with one I got off the forums here.

I just barely tapped it and it went out. When I tried to remove it it broke and I had to chip it out manually with a pick, then when I bought a new one it wouldn't fit.

So.. I went to superbright LEDS and I picked up some of these:

(non-sponsor link removed)

in case the link doesn't work, they're 74-CWHP3.

I noticed when swapping my door panels that they too had lights! I had no idea. also 74-CWHP3.


My camera is terrible at picking this up. It's actually quite bright.




This went very well, so I decided I wanted to go all the way with LEDs.

But first.. there's something I want to tackle.. and that is the foglight switch.

So I have a parts car.. I dug around in it and got the switch out to see what kind of bulbs I'd be dealing with.

Here's what's inside the foglight switch:



Those are 2 tiny ~74 sized incandescent bulbs with colored sleeves over them, with long leads coming off of them. They're soldered onto studs in the button plastics.

Has anyone tried this swap before? (the foglight switch.) Seems simple enough to me, but I'm no electrical engineer. I figure, go to radioshack, get the right size super white LED for the center, then probably a blue one for the on position light with long leads on them, cut these leads, then solder the new ones on.. as long as they're 12v it should work right?

This is a low priority project, but I want to document the conversion here as good as I can (if someone has already done this point me in that direction please, and I apologize in advance for my repost.)so that others can follow it if they wish to do the same thing.

Our cars aren't getting any younger, and it's only a matter of time before these small bulbs start going out on us.

Also, something to note that you probably already know. The silk screening process for camaros involves putting a blue overlay under the white. red on pontiacs. The blue in the camaros makes the yellow incandescent bulb light the gauges white at night, but when you go LED it gives them a slight bluish tint. It's not offensive or anything really, but it is different.

VIP1

LEDs generallv are in the 2V - 5V range (a high percentage are around 3V). You'll need a resistor to cut the voltage down to what the LED needs.

You can use a LED Calculator such as this one: http://led.linear1.org/1led.wiz to determine the resistor that will best suited for your application.

You just need to know 3 things:
LED's recommended running voltage
LED's draw current
Supply Voltage


Here is an example white LED....

LED
* 3.5V Forward Voltage
* 20ma Current

Supply Voltage
* Car's Voltage... varies 12V - 14V.

So entering that in...

If we calculate for 12V, then we need a 470 Ohm 1/2 watt resistor.
If we calculate for 14V, then we need a 560 Ohm 1/2 watt resistor.

Get something between those two to be safe. If you typically use the dash lights on a lower setting, then you can go with the lower rating. I have my dash lights dim so the lower rating would work fine for me. For the example above, that means the 470 Ohm 1/2 watt resistor would be sufficient.

Now that was just an example. When buying parts, make sure you get the correct resistors that will work with the LEDs you buy. Check the sepcs of the LEDs and buy the matching resistors.

If you do find LEDs rated for 12V, it just means that there is already a resistor soldered in-line.

Also, LEDs are polarity directional. They only work in one orientation. If it doesn't light up, swap the positive and negative. Solder the resistor to the positive leg of the LED.

Regarding the colored sleeves, get the LED color you want and ditch the sleeve. At that point it won't be needed anymore.

DarkFox118

iTrader: (7)

Hrmm, that poses an issue doesnt it? The size of the switch is pretty small inside. I mean how big is the resistor? There's a LITTLE bit of space underneath the bulbs (very little..) and there's some space beside the clips.

yea i wasn't going to worry about the sleeves. i'm kind of surprised this is incandescent, but I guess in 2000 LEDs weren't common.

VIP1

The resistor might fit under there (I think others have done it). If not, you can have the resistor be outside of the switch and run wires inside through new holes in the back.

DarkFox118

iTrader: (7)

OK, I put the switch into my parts car today and promptly screwed up and blew a fuse.

In case you're wondering, its the dimmer fuse, 5a in the panel in the driver's door area.

Anyway.. I replaced the fuse and was more careful, looks like both bulbs are pulling 12-14v as we had expected so to make this work I'm going to need a small resistor for both LEDs.

What should I be looking for? and is this something a novice at soldering should attempt? I have a friend that's a lot better at this than I am, I'm wondering if I should enlist his help for this.

VIP1

My first post above has a good LED Calculator to help you get the correct resistor for whatever LED you get (I use that calculator).

I can't tell from that pic if a 3mm or 5mm LED will fit. You'll have to take the switch to the store to check.

It's not that difficult to solder up some LEDs and resistors. Check out some other threads to see the brightness of other LEDs people have bought. I've seen people use 3000MCD to 8000MCD. 5000MCD should be plenty though.

DarkFox118

iTrader: (7)

Thanks. I used the LED calculator, and picked up a white LED and a resistor from radio shack.

like your example it was a 3.5v 20ma LED. I also got a pack of 470ohm 1/2 w resistors. The whole thing (plus a blue LED I didn't use cos I was playing around with ideas) cost me like $14.

This weekend I took to the switch and soldered it up.

I decided not to replace the amber incandescent bulb. After doing the white backlight bulb it was apparent that my soldering skills, coupled with the need for an additional resistor, was going to be too tight a job for my skill level.

UNFORTUNATELY.. I did not take any pictures of the process, as, I burned my finger, cursed many times at my obvious noob skillz, and got carried away when it worked and snapped it together.

Once it was all done however, this is the result (taken with crappy camera phone.)



It's a very clear, clean white. I had to remove the small plastic tube that the blue icandescent bulb was sitting in because of the LED's base. The increased size of the LED however, plus the close-ness of all the extra wire made it fit very snugly when it was assembled.

The resistor sits outside the switch on the top. (when looking at the switch, the terminal closest to the switch itself is the positive.) I dremeled away the entire side of the switch assembly to make room for this so that it wouldn't cause a problem.

My only concern is that the wire wraps very close to the lead sticking up from the switch assembly BEFORE it hits the resistor. If it were to touch the lead, the LED would get a full 12-14v signal. I'm not sure what would happen then. I may go back in and try to insulate this for safety. If I do, I'll take pics of the results.

VIP1

If the LED gets the full voltage, it will burn out quickly. It may flash and smoke as well.

If the positive and negative touch that will blow the fuse (hopefully before burning anything).

DarkFox118

iTrader: (7)

well, there doesn't seem to be anybody but you and me on this thread, so.. I guess I'll stop updating it. Thanks for the help tho. It's working quite well. When I get the opportunity I'll insulate the 3.5v side of the resistor from the 12v lead.

VIP1

Although others may have not commented, there may be some out there that may find this helpful. Especially if someone does a search. They may find this thread and it may help them out.

NBMcamaroSSdriver02

I was following this thread, I've been meaning to do this to my steering wheel controls and fog light switch. Looks good!

DarkFox118

iTrader: (7)

Oh, good call on the steering wheel. Are those supposed to light up? Huh.. I've never noticed them. I have an aftermarket deck so they don't work for me anyway.

It was surprisingly easy, and I'm terrible at soldering so that says something. Also, the tip of my pencil soldering iron has a notch in it, like it's melting in half. so it holds a good bit of solder within that groove, sometimes accidentally scraping solder away from my work. So if it was easy despite that, I imagine anyone can do it.

VIP1

You can get an adapter to have the steering wheel controls work with the aftermarket headunit as long as it either accepts a wired remote input or has an IR remote.