Ideas for LED tail light retrofit

[Monoxide MS]

I've been working on a lot of LED projects lately and was looking for another project to take on. My brother has a '95 Avalon XLS and said he wouldn't mind having a set of LED tail lights. It looks like there isn't much aftermarket for this vehicle, so you guys are probably used to making things yourself. For this one, I want it to be slightly noticeable, but still look period correct for this mid 90's Toyota. Nothing wild like what's being seen on todays late model cars.

A lot of people don't like LED's behind a pillowed lens because is distorts the lights. IMO, it makes for a really cool effect. I call it the "digital" look, since it sort of resembles those RGB LED signs.

This is the tail light on my car that I retrofitted with Lumileds Superflux LED's.


Someone else's 2G Eclipse. (not my work)


I did a mock-up of a design that I think would work well for this car. Basically sting a few rows around the brake housing for a parking light and then have it to go to full brightness and fill in the rest of the area when the brakes are applied. Another idea was to keep the parking light string dim all the time and only allow the center to have full brightness.

For the turn signal, I was thinking just a solid array would work fine. Possibly do something sequential like the late model Mustang, but I need to open the tail light first to see if they're wide enough to make this worth the while.

Animated .gif for '95 Avalon.


I haven't seen the 97-98 tail lights up close, but that could be another option. I know there was a mid-model update around that time. More red in the tail light and the turn signal has an amber lens. In the photos it looks like the pillowed effect is more smooth, so LED's may or may not look better in those housings.

The plan is to use either Superflux LED's again or try a surface mount PLCC-4 model by Osram. I accidentally ordered the wrong color and now I have several hundred red/orange Osram's that I need to find a project for. These are made specifically for automotive use, so there shouldn't be much problem with heat or brightness. I'd still like to do some testing to verify.



Everything will be contained inside the tail light if I move forward with the surface mount LED's. There will be plenty of room on the backs of the PCB's to fit the PWM dimming circuitry and voltage regulators. If the Superflux LED's are chosen, the additional circuity will likely need to be mounted externally in a weather proof box.

Lastly, I wanted to use some power LED's with optics for the reverse lights. I'm using some 5 amp SST-50's in the reverse lights of my daily driver (1300 lumen per emitter). For the Avalon, we might try putting 2 Cree XM-L T6's in each housing. It would be brighter by a slight amount, but much more energy efficient.

That's all I have right now. Looking for ideas and doing some testing. If this works out, I can share the PCB design for the DIY'ers out there. Maybe even complete a few extra sets for those that want the same design, but don't want all the added work of doing it them self. I'll be sure to first check out forum rules before doing anything like that.

[kingnba6]

i have a friend, more like just a buddy. he fitted leds in his motorcycle tail light.
he took led strips and mounted them/ i think it was about 5 strips in height and about like 8 or 9 leds width. he connected a board to make the outside strips to run as drls. which you have done and then he connected the rest for brake with a brake module to pulsate the light when stopping.

[Monoxide MS]

Yeah, the prewired LED strips seem to be a popular mod. I haven't used them personally, but have seen all sorts of creations with them from browsing the forums.

[pmesfun]

Looks cool. Subscribed.

[Jigg007]

Awww shiiite.


I've been entertaining the same idea in the back of my head for a long time, now I got to pick up the pace before someone beats me to it!

I was either going to bake the lenses off or just dremel the rear of the housing off, and make my own backing out of either lexan or thin stainless to hold a massive array of LEDs very similar to yours. I've already used the baking method to disassemble the front turn signals and build an array of 42, 5MM leds. Which I agree with you on the whole "digital" look from the Fresnel type lens is pretty cool looking. Interested? Video

But lately I've been toying with the idea of getting a dozen 0.5 or 1W luxeon type for each tail light, a lot less work, thats for sure.

I looked at the spec sheets for both those high power leds, and 1300 lumens is a bit off

[Monoxide MS]

Awesome work on the sequential turn signals! Those look really nice. My brothers Avalon is also black. Is that an analog circuit or are you using a micro-controller? I haven't build one yet, but have the diagram for an analog circuit and it looks pretty straight forward. Just a decade counter and a handful of supporting components.

My brother is off work tomorrow, so I plan to take apart the tail light and start taking measurements. Hopefully these come apart in the oven. It sucks cutting up lights. My front turn signals had to be cut open and while the silicone seems sturdy, I'm just waiting to find water inside them or a missing lens.

High power LED's would be cool. Very few guys go that route. I think as long as the design looks good, why not? Like you said, it would really save yourself a lot of work. I have a single 70 lumen red/orange Luxeon Rebel in each one of my corner lights with a side emitting optic glued on top, and they work great. A single LED took the place of 40 low power Superflux's.

Well today my order of surface mount Lite-On brand LED's arrived. They were on sale for 9 cents a piece so I order 400 of them to play with. They are very low output (1050 mcd), but the narrow viewing angle of 25° seems to make up for it. I took 4 of them and placed them on a thin piece of copper clad circuit board and reflow soldered them on the stove with a frying pan. Then I set up a little test with 4 Superflux LED's to see how they compared. Surprisingly, the brightness appears the same. If the tail lights are deep enough, the narrow viewing angle might not be a problem. Plus they require less current, so they'll run cooler.

TOP: Superflux (70 mA)
vs.
BOTTOM: Lite-On SMT (32 mA)

[kingnba6]

high power leds would be nice. just got to be worried about the lifetime of them and buying a good brand. you dont want to cheap out and get leds that burn out as soon as you hit the road

[Monoxide MS]

^^ Agreed. Especially with something important like a cars tail lights. The generic Chinese emitters are attractive from a cost per lumen stand point, but it's hard to tell how long they will last.

Today I made some progress on the Avalon retrofit. First the tail light in the rear dash was removed. That was really easy. Much easier than I had anticipated. It's just a few clips. Next I moved onto the passenger side tail light. Also very easy to remove. I looked it over and noticed that it's held together with the same type of adhesive as my '97 CL. Both cars have tail lights made by Stanley, so that makes sense.

I popped it in the over at 220° F for 6 minutes.


It was starting to soften, but it required 4 more attempts at 4 minutes each before it finally came apart. The adhesive is not like the butyl rubber used in most headlights. It's more like old chewing gum. Almost plastic-like.

Here's the insides.




These tail lights aren't as deep as I had hoped and it looks like the Lite-On LED's won't be used in this retrofit. They might work in the upper 3rd brake light, but the two other will need the brighter and wider Osram emitters.





Unfortunately, time was limited since my brother had plans today, but I was able to take measurements and draw up a template. The brake light template was the easiest. I just removed the diffuser and traced over it. Simple enough.

The area around the corner light is very tight and will be the biggest problem. I'm not even sure that these tiny surface mount LED's will fit, even with an ultra thin PCB. There is a reflector that takes up most of the room, so I may have to use a single high power LED like the Rebel. This sort of messes up the design of the parking light.

Here's a photo of the template. I drew in the areas where the reflectors are the deepest. That's where the dual brightness circuitry will be placed on the backside of the PCB.



This is the reflector in question. There's also 6 rectangular shaped reflectors in the brake light that appear to be positioned out of the way of the parking light "ring" array.



So that's all we have today. Tomorrow I'll try to draw up the traces and etch the PCB. Hopefully next weekend I'll have an array to test fit.

[CTB727]

Looking forward to the progress on this project.

I just did a simple plug and play for the LED's on my taillights. I used the Platinum series bulbs from V-LEDs as they are the brightest and best quality you can get for a plug and play LED bulb. They are quite pricey at $80 a pair, but luckily I snagged them during a 5 minute 50% off sale that'll probably never happen again

http://s725.photobucket.com/albums/w...t=MVI_0664.mp4

[Monoxide MS]

Look really good. That's the first I've heard of those. The Elef bulbs are also very bright. They use either a 3W Luxeon or 5W Osram emitter.

Are the updated tail lights a direct swap on the 95/96 Avalon? It doesn't require the bumper, trunk and quarter panel to be changed, right?

[pmesfun]

^You need the trunk lid from a 98/99 Avy and rewiring to the trunk.

[Monoxide MS]

Ah, I see it now. Part of the tail light is in the trunk lid. Thanks.

He probably won't go for that. Looks like we'll stay with the original lights.

[Jigg007]

Originally Posted by Monoxide MS

Awesome work on the sequential turn signals! Those look really nice. My brothers Avalon is also black. Is that an analog circuit or are you using a micro-controller? I haven't build one yet, but have the diagram for an analog circuit and it looks pretty straight forward. Just a decade counter and a handful of supporting components.

First attempt at the project I used a latch, 555 timer, and a decade counter, and obviously a handful of transistors. That was wild, and glitchy. Later in time, one of my friends wanted to use his exxxtreme C programming knowledge to make some cool PIC/microcontroler circuits. If you want to build something like this let me know, I'd be happy to help.


Heres the controller for the LEDs


But of course, with a programable chip, adding features is as simple as a few lines of code, verses half a dozen logic ICs.

dat youtube


I really like how easy it looks to take apart those taillights, I didn't want to do mine during winter, but you're doing a good job persuading me otherwise . Etching PCBs? I'm so jelly, moving away from pref-boards to making my own circuit boards would be so cool, but I'm too intimidated by jugs of chemicals lying around. Not ignoring the time to create the layers, and different stages in the etching, its probably a lot easier and maybe quicker than pref-boards, especially for reproduction.

[Monoxide MS]

Nice work, that's something to be proud of. I've also heard the analog circuits can be tricky. Learning the code for the micro-controller sounds a bit intimidating. I've never tried programming outside of the web stuff. Just javascript and actionscript from a few college courses, but I've been told it's somewhat similar. I'll probably shoot you a pm when it gets to that point.

Etching PCB's is a nice thing to learn. I moved onto this just because it looks more professional when it's completed. To be honest, it doesn't really save much time when you take into account the designing of the layout, the transfer, the etching and so on. Using software specifically for circuit design might speed things up a little bit. I use Adobe Illustrator which works pretty well, but getting all the dimensions correct really eats up a lot of time. Like you said, the real benefit is probably in reproduction.

Today I got most of the 3rd brake light completed. I wanted to give the low output LED's a try and came up with this simple design.





I reflow soldered the LED's on the stove with a frying pan. They came out pretty well. It took forever getting them lined up correctly. I need one of the professional pick and place machines.





The voltage regulator w/ heat sink, resistors and filtering capacitors are on the back.



Tight fit, but works ok.



These LED's are surprisingly bright! Not bad for a 8 or 9 cents a piece. The narrow beam pattern isn't a problem with the OEM pillowed lens in front of it. It does a good job of dispersing the light.



Also, I have some empty 194/168 plug-and-play bulb bases to make the install a little easier.



That's it for today. There will probably be more progress this weekend. Maybe start on the tail light design, or maybe a redesign of the 3rd brake light array.

[kingnba6]

skilled people on this thread i can see. congrats on the tail light.

and yes reproduction is where the money comes from.