LED taillamp project thread
 

Hello all, I figure I'll post info and photos as I go along on my project. I'm converting my rear lamps to LED to improve output and visibility, and to modernize the look a bit. I'm taking an approach on this project that I want the look to remain OEM, and I want an improvement, not downgrade, in the lighting.

I'll be using components from the 2000-2005 Cadillac Deville. I chose this rather than going to the aftermarket because of the look they produce. I feel these are closest to what Audi would have done during that era, and I feel these are excellent lamps. Here is a photo of the brake lamp on the Deville illuminated:

http://i631.photobucket.com/albums/u...0CB5931E82.jpg

These lamps produce this look because of a Fresnel lens placed behind the outer red lens. This provides a pretty even, completely illuminated look. The outer lens is pretty damned identical to the D2 lens.

I'm going to keep the segmenting of the D2 rear lamps. Rectangle of turn signal, rectangle of brake and running lamp, then in the boot rectangle of running lamp and then rear fog. This will mean I have roughly 21 LEDs and 21 tiny Fresnel lenses in each pocket. I'm going to experiment with amber and green LEDs in the turn signal to produce amber (in US-spec cars the turn is red normally). I'm going to place 2-4 LEDs in the corners as well to maintain US side-visibility standards. Those will be exposed rather than behind a Fresnel lens.

Here are some photos of the Cadillac lamps opened up in order to better explain what I'm saying.

http://i631.photobucket.com/albums/u...0B9B4D0798.jpg
http://i631.photobucket.com/albums/u...0B90B209F3.jpg
http://i631.photobucket.com/albums/u...0B4F1A74D9.jpg

Using wiring diagrams from my shop's All-Data system, and some trial and error, we figured out what pins on the current board illuminates which LEDs. We used a DC test station to determine amperages, and voltage needed to illuminate at acceptable levels (12v for brake lamps, and for running lamps we found 8.5 volts to be correct. That means an in-line resistor will be needed for running lamps and that will be bypassed for brakes).

I've opened up the boot lenses already. To do this I used a soldering iron with a cutting tip. I'll clean the cuts up and make them more attractive before sealing them again, so excuse the jagged appearance for the moment (when held together/redeemed the cut will be invisible anyway. Also, a larger, clear, inner-lens was removed from the brake light (single Fresnel-style).

http://i631.photobucket.com/albums/u...0B5EC603C1.jpg
http://i631.photobucket.com/albums/u...0B700DD649.jpg
http://i631.photobucket.com/albums/u...0B8338DFB0.jpg

As I begin cutting the LED panel and placing the diodes and as I do the same with the tiny Fresnel lens I'll update this thread. I think I did ok for one day though, working this in with my actual duties at my shop.

Also on the agenda is another little LED/styling project I've begun- using D3-style fender repeaters. Today I removed the belt molding, cut in the repeater, started trimming the aluminum trim, cut out aluminum to be welded into the current repeater holes, and began the plastic repair/molding on the belt trim to make the fit correct. That should be a great looking modification when finished.

Interesting, but a bit too intrusive for my taste.

The 'mod' I do with my rear lights is I polish out all letterings/messages on them (3M 600 sandpaper with water and then Meguiars PlastX polishing compound). Afther this process lights surface become absolutely smooth, don't collect dust and nice to touch and to wash. I understand this can be illegal, but i've passed a couple of MOTs so far without any problem.

Interesting mod - partly from a point of view of understanding how newer LED lamps are put together and partly because this is looking like the closest when complete to how the original lenses were lit (I've seen a few others where the completed lighting looks quite different shape wise.

Thanks for documenting, following with interest! +++

Intrusive certainly doesn't bother me in the least. Here's my Camaro in a during and then after photo of the restoration process:

http://i631.photobucket.com/albums/u...3C05D5C572.jpg
http://i631.photobucket.com/albums/u...eafbf369b2.jpg

I've done something similar to what you're saying as well on the taillights on my Scirocco 2. As you may well know, they have ridges in the outside lens, so I sanded those off, then sanded to a fine texture, then sprayed the complete housing with HOK Candy red (it is a transparent red that matches OE rear light color quite nicely). This tinted the turn signal as well, which was my desired look. I don't have any photos of that right now.

I've seen the Russian setup On YouTube, like the concept, hate the execution. I want something effective, but understated and elegant, like the D2 itself. I think the newer Audi taillight designs are rubbish. Here in the US we'd compare them to what is available on eBay. Basically, I'm fighting to put modern tech into the D2 shape. I'd do much the same in an e38 BMW. classic designs, elegant, not frumpy and over-designed.

Well, after playing with the Cadillac lamp, I found it just won't work. I'm therefore going to be building an array on a printed circuit board using these LEDs (going to start with roughly 350 and see if that is enough/too many)

http://www.mouser.com/ProductDetail/...PybykHUWTzo%3d

I'm consulting a gentleman that's built several of these before, here's a couple different boards he's built for Acura TL lamps (a Honda product for you guys I think)

http://i203.photobucket.com/albums/a...ayFinished.jpg

http://i203.photobucket.com/albums/a...ntComplete.jpg

And here was a final result:

http://i203.photobucket.com/albums/a...ailDigital.jpg

With the fluted lenses we have on the D2, light output should actually be even more even and will most definitely be very attractive. I'm going to run 50% more LEDs on the board than on the second PCB I have pictured, so, as I said, light output should be VERY even. Here in the States the rear turning signal was red as well, and I had considered running a different color in order to get an amber turn, but I'm going full red. I also may play a bit with what portions of the lamps illuminate in different combinations (i.e. the complete red portion illuminates when taillamps are powered, including the rear fog section and turn signal area, and when those are operated the intensity rises.

If you crack this, I want first dibs on a duplicate set! that last pics is a nice even light, much more OEM

I'll be honest, it's really overwhelming at first, but as you get going on it everything becomes a bit more clear. Certainly is confusing without knowledge, but, like most other things these days, the information is more than available, just takes time to digest it all.

Well, another update: I ordered LEDs to use, but they're so bloody small I don't think I can use them. Will be ordering another style. Frustrating.

Are you thinking of going with surface mounted LED's or 3,5-5mm LED's with pins?

Hmmmmmmmm now what about a full set of rs6 avant ones :p ..........I dont like the ones that are available on tinternet!