Taillights With Leds - BMW Forum

Paraklas · 10-26-2004, 02:21 PM

I have an E30/M40 1989 318i (Euro Spec).

I’m working on a mod now, which is replacing the stock bulbs of the tail lights with custom (made by me) high power Led clusters. I was thinking instead of placing 8-9 LEDs in the space of the stock bulb, to place an entire cluster of LEDs that would occupy the whole tail light. What I mean by that, create a cluster of LEDs for the reverse lights, another one for the stop lights etc, but each cluster will have dimensions as long as the actual taillight part.

I have enough board, LEDs, time and solder with only a few concerns:

How many parts is the taillight assembly after removed? Can I remove the back cover so that the White, Yellow, Red plastic are totally exposed from the inside?

I want to know this because; if I can’t remove the back (I don’t want to cut it) cover, then the only room available for LEDs will be the small holes that are just as big as the stock bulb diameter.

If the cover along with the light reflector can be removed, then I will place the leds close to the red/yellow/white plastic, place the cover back, and then put the taillight back on the car.

If i can pull this off I believe that it would have no difference from buying the expensive taillight led assembly.

If everything works I'll post before/after pictures.

Paris

witeshark · 10-26-2004, 09:28 PM

I have been lookng for ways to do that too. LEDs are better lights.

jaymz · 10-27-2004, 02:19 AM

was thinking about this myself today,,keep us updated on how it goes

Aether · 10-27-2004, 05:37 AM

Hmm, never thought of that sort of thing being done to an E30.
Eager to see the result. Good luck!

Paraklas · 10-27-2004, 11:10 AM

I have one problem though cause I don't have the car with me right now.

Can I remove the back cover so that the White, Yellow, Red plastic are totally exposed from the inside? This has to be done in order to put a full length LED board from the inside.

Thanks!!!

Paraklas · 10-27-2004, 04:15 PM

Problem solved... Got a pair of used but original BMW tail lights from ebay ($50 total) that I will modify accordingly to accept the led clusters.

Pics to come after I receive the items.

wcleafs · 10-27-2004, 05:46 PM

I would be interested to see, I changed the dash lights in my E21 to blue LEDs
much easier on the eyes and rather sharp looking.

Wouldnt mind seeing your schematic and the resistor values
would like to re do the brake lights on my girl

Good Luck

BMWJNKY · 10-27-2004, 09:23 PM

Thats a good idea but you may run into one problem. You check bulbs light may be on all the time. The check control system knows how much resistance is in the wireing system, if you don't have enough or too much resistance the check bulbs light will come on. You will definatly need to install resistors in the turnsignal LED's cause if you don't they will blink really fast.

witeshark · 10-27-2004, 10:12 PM

How sweet! Can't wait to see results I wanna do the same on mine

wcleafs · 10-27-2004, 11:47 PM

Resistors are required in the LED boards to limit the current to the LEDs as most of them run at 2.5 to 3.5VDC, I am not completely sure but I think the blinking is a result of the charging and discharging of a capacitor in a relay circuit. Perhaps someone more knowledgable could answer that. I would assume that the resistance of the curcuit could be figured out to a fairly close value. I think all you would have to do is match the resistance of the turn signal bulb (specs should be available) I could also be a function of current draw on the circuit. Oh great now I'm just rambling.......anyway I am rather interested in all this. I want to find some more uses for LEDs in the car, I think I will replace the bulb in the interior light. there are bayonet type bulbs with 3 LEDs on them that fit in the socket. but figure I can do just as good of a job.

Fox · 10-27-2004, 11:54 PM

cant seperate the light housing you have to cut the back and make a holder for the silicon board.

I did this last year with my e30. The check light didnt come on for me but thats because i used the correct resistors and such. It doesnt change the look of the brake light at all so dont even bother redoing that, the brake light has the light diffusor in it so it looks exaclty the same. It changes the look of the normal parking lights but not drastically. This is due to the ripple in the plastic. If you need any help ask.

If you remember someone brought htis up and i was the only one to go ahead with finding out how to do it. And i used 42 leds per parking light.

Paraklas · 10-28-2004, 03:02 AM

Do you have any photos to post us here to see the results? What kind of LED's did you use?

Paraklas · 10-28-2004, 05:26 AM

Even though it may seem harder and more time consuming, I thought of removing the light reflectors from plastic - don't know exactly how but I believe it can be done using sandpaper and then just enough heat to make the plastic smooth and shiny again, maybe some plastic restoration product.

This way I'll have a flat, light-reflected free, tail light to put the LEDs behind without worrying about the light reflected elsewhere.

What do you think of that?

Quote:

Wouldnt mind seeing your schematic and the resistor values

As soon as I calculate how many leds I'll let you know about resistor's Ohms/Wattage etc.