starting project for led switches

[compudude86]

so I am starting to convert the LEDS in my door switches/window switches/lock switches. I will be trying to make a tutorial on this for everyone because it seems I cannot find one here already and I feel I should share with everyone wanting to do this.

so far, I've popped the switch apart, poked around a bit, hooked it to the harness with the cover off and probed it with my multimeter (this is a good investment for anyone who works on cars. it is invaluable to see what is going on voltage wise on your cars electrical system and making repairs to it. they sell them at radioshack(expensive) home depot, lowes, i'm sure most hardware stores, I believe harbor freight has them, you can get them almost anywhere online) and I have found what I suspected would be true. the illumination circuit before the resistor shows me 11.9 on battery, and after starting the car, jumps to 14.4 volts.

"12 volts" is no longer the case for the cars illumination circuit. back in the day, when everything used filament lamps, 12 volts could and would vary and wouldn't be an issue as the lamp was good for about 5 volts extra give or take before it would burn out. Im also going to take a stab at the possibility that older cars/alternators ran lower voltage as well but I could be wrong. However, with higher power alternators driving higher power ignition and controls under the hood it has become the norm to see around 14 volts in the car.

so what happens if you go ahead and use resistors matched to 12 volts? I can speak from experience. first few days, they will run great. as the week goes on, your LEDs will burn out completely, one by one, or you will see them begin to "hyperflash", or flicker on and off, then start to blink really fast and dim, right before they go out for good.

on my setup, I am compensating for a voltage of 15. will this dim my LEDs some? especially when the car is off and the voltage drops to 11.9? probably. but I guess it is a small loss compared to spending all that time soldering and replacing LEDs just to have to tear it all apart again to replace burnt out or flashing LEDs.

 

[JRoX85]

You don't need to buy new resistors, stock ohm levels work just fine so you can reuse them. You will need 3mm 5volt led's and a solder gun with thin solder. Mine have been in for 3mnths with zero problems. I have detailed piks and writeup already saved just have not posted it. I am also a low voltage technician by trade.

P.S. Bought mine from autolumination

 

[Matt R]

I did a group buy a few years ago for doing these. Get whatever color 3mm LEDs you need from eBay and 560 ohm resistors. Replace both, making sure you keep the anode/cathode of the LED the same as the original. I suppose you could use the stock resistor but it's not really rated for what you need. I did mine in blue (and numerous others in various colors) with the 560 ohm resistors, and I'm going on 4 years now without any problems or color changing.

The main switch is a little more difficult, you'll need to replace the 4 LEDs, then replace the 2 resistors connecting the 2 halves.

 

[compudude86]

ok, well that was an interesting project. I would've taken pics but it can be quite a pain to install the leds and solder with the two hands I have and the camera would've made it very difficult. the single switches, with my experience in electronics, was pretty simple. only had an issue with my U/L switches not lighting evenly, in moderate/overcast light the lower light would be very bright and the upper would be dim. so I had to bend the LED up a bit (thanks Matt R) and "chew" out some of the white plastic shield on the back side of the button, but I need to do the "night test" to make sure it is even in the dark. however, the master switch, was an absolute bear. fairly tight areas to solder in, I had a few parts that the solder refused to stick. I used 2.3v leds (sorry, I cant for the life of me find 5v leds in new colors) and replaced all but the red LED, and now that is dim due to the resistor change (probably a 5v led) but once I find where i hid my red 2v LEDs it will be changed. I just got a cool idea, though I wont be doing it on my car, to change each window switch in the master to a different color, and then put the same color from each master into the corresponding individual switch.

also, a tip for disassembling the switches: I used thumbtacks inserted between the two tabs on each side (do the flat side first then the side with the notch it seems easier) then pull each half, button side down, gently, as if you do it too fast the brass switch tabs will fly away and disappear until later. leave the button half face down on the table to retain the brass tabs. the big switch doesnt really need it, but the first time i cracked it open I used the tacks. watch the window lock switch piece inside the master, this is also another easily lost piece. it goes back in "pointy" side down into the holes, the "bumped" side meets with the "bumped" side on the contact attached to the master, place the lock switch into the "open" position, flip the spring loaded slider inside down, and when you reclose the switch make sure the slider is fitting down on the lock switch. confirm that it works before connecting by sliding it, it will feel normal and click back and forth, if its not seated it wont click, and when you shake it, you'll hear it rattling around.