[UK_Nomad]

Originally Posted by brutis

Is there a part number to just buy a new board with the wires etc on it already rather than changing out the LEDs?

The photos above show a part number on the board (note left & right have different part nums).
You could try and order them at your local dealer - let us know how you get on.

[martin4179]

Firstly, congratulations to UK-Nomad on a first class guide to what is clearly cost effective solution to an expensive problem.

After reading his post I undertook this work myself, but was wary of splitting the lens from the rear of the unit. Instead I decided to try and do it by just cutting out the back of the light unit where I imagined the circuit board to be. Using a Dremel I made a couple of trial cuts to work out where the board sat and then cut around it.

Once I'd exposed the board, I cut the blue and brown wires to remove the unit. I'd ordered a pack of 10 x 5mm Ultrabright LED's from eBay (led-essential) for under two quid. I don't work for them but I will say that they were really helpful in identifying the best ones for the job and would recommend them.

I unsoldered and removed the old LED's (including the working one - I wanted a consistent light), and refitted new ones on the original nylon blocks. My soldering skills are poor, but I found if you put the pins through the board and bent them at 45 degrees in opposite directions (see picture) they stayed in place while you solder them. Snipped off the long tails and tested with a 9v battery. The original LED's are white but glow red. Replacements are white and glow white, so I painted them with red acrylic.

Put back in tail light and siliconed all bits together. To be honest, they are slightly dimmer than originals but at least I won't be pulled over for two bars out. MOT in November - I'll let you know if any problems!

[Sampan597]

Hi, I have the same issue on my (pre-lci) E93 2010. The 3 strips on the boot lid tail light aren’t working. But others are. To get this fixed would I need to get the whole unit or can I get a simple led bulb change?

Thanks

[Ziomek232323]

Guys, I know this is an old thread but maybe someone is still reading this. I have a problem where all 3 of my LED's are working but just arent as bright as the other side tail light. Any idea what can cause this ? I tried to connect the tail light using the other side connector plug and still the same, so i guess that rules out a bad ground or issue with the wiring, seems the problem is with the headlight itself. Any ideas ?

[Gii]

Originally Posted by Ziomek232323

Guys, I know this is an old thread but maybe someone is still reading this. I have a problem where all 3 of my LED's are working but just arent as bright as the other side tail light. Any idea what can cause this ? I tried to connect the tail light using the other side connector plug and still the same, so i guess that rules out a bad ground or issue with the wiring, seems the problem is with the headlight itself. Any ideas ?

Its possible that one of the LED's its on its way out, and gives extra resistance, so the other LED's follow being darker.

[gourtz]

very good guide.

[Liam_M1]

Although an older post, this guide has just helped me to fit new LED's in my E93. Cut the back from the light away to reveal the board, use a 9v battery to identify the dead LED, de-solder then re-solder new.

[CweLe]

Great DIY, thank you!

[wdb]

Keep this thread alive, ooh-ooh, keep this thread ali-i-ive...

The taillight LED went out on me, and after reviewing this information I decided to just bite the bullet and buy a new unit for my 2007 E93. Which means I have an old right-hand side outer taillight unit available FOR FREE to anyone who wants to hack it open and/or maybe needs a second try at getting one right. Just pay shipping. I figure it will be about $20.

[wdb]

my free taillight has been spoken for.

[GSB]

I wish the OP would update the thread title to include the E92 taillight, because it has the same basic design.

My taillight LED bars started dying one by one fairly recently. LEDs are supposed to last 50,000 hours or so, which is 5.7 years if they burn 24/7. So what shortens their life? HEAT. In the fierce heat of a car, LED life will be shortened, especially if heat-sinking is inadequate or if the LEDs are running during the heat of the day.

I found replacement taillights at FCP Euro for $185 each, which seemed reasonable enough, and seemed better than repairing my old ones because the lenses were crazing with micro-cracks from the sun. But there's something funky about the color of the new taillights! Instead of the cherry-red color of the originals, the new LEDs tend toward amber. It's reasonably subtle, but it bothers me because it doesn't match the trunk-lid LED bars very well, as can be seen in the picture below.

So, I decided to hack the brand-new taillights to replace the LEDs with RED, rather than the unfortunate amber-red color. I'll document the process more exactly in subsequent posts, because it's easy to screw this up!!

[GSB]

The LED bars are clear plastic "light-pipes". The idea is to aim as much light into the pipes as possible, with as NARROW a beam as possible. The light-pipe will carry the light all the way to the end, like a fiber-optic cable, while the little ridges along the surface of the pipe will allow an even amount of light to escape along its entire length.

In the borrowed picture below, you can see what happens if you use an LED with a wide viewing angle. Light disperses too quickly at the start of the light-pipe, and grows dimmer along its length.

It's important to order an LED with a viewing angle of 15 degrees or less, AND a luminous intensity higher than 10,000 millicandela AND a power dissipation of 120mW or higher AND a peak/dominant wavelength of 625nm (real red). This pretty much excludes all 3mm LEDs. Light-On makes an excellent 5mm LED that works perfectly in this application, and it is available fairly cheaply at Digi-Key. I've included a picture of the LED that fits the bill and currently gives the best bang for the buck...

[GSB]

Separating the red lens from the rest of the assembly is fraught with all kinds of hazards, like cracking, warping or melting. Cutting the case is problematic too, because cutting in the wrong place can damage the circuit board or many of the small plastic features that hold the board in the right place to aim the LEDs.

Unfortunately, cutting with a thin coping saw or Dremel tool creates millions of microscopic plastic particles that become electrostatically charged, and that static charge sucks them deep into the lens assembly, where they stick and look bad from outside. It's almost impossible to suck them out with a vacuum or blow them out with compressed air, because the static buildup seems to worsen. The cleanest way to cut the case, is with a very hot and sharp blade. I had to use a heat-gun on the highest setting to heat the blade sufficiently. The blade will turn dark colors of purple and brown, so use a strong, thin, disposable blade.

Here's where to cut, so as to miss all of the delicate stuff and get it right first time...

Mark a straight line across the case, through the very corner of the square date-code-grid molded into the case and the middle of the feature I've marked with red lines and arrow. Also cut all around the bottom of the case where I have marked. Do not cut too deeply!

[GSB]

Do not attempt removal of the circuit board by prying either side at the red arrows. It will break the tiny plastic tabs holding the board in place, which is a problem when it comes to reassembly and aligning the LEDs.

The only way to prevent damage is to press the board down at location (1) while inserting a very thin blade at location (2) to lift the board gently. The board should bend slightly. While still pressing down at location (1), shift the board to the left to clear the plastic stop at location (2).

[GSB]

Removing the old LEDs takes some skill. Unfortunately, it is extremely easy to rip the thin copper traces off the board by trying to pull out one leg at a time or by prying too hard. Melt the solder on both legs at the same time and pull it straight out. Be careful, it'll be HOT! Then use desoldering wick or a solder sucker to remove the old solder and completely open the holes for the new LEDs.

Before bending the legs of the new LEDs, make sure that their polarity is correct. LEDs are diodes that will only light up in one direction. ALL of the LEDs are bent the same way, for BOTH taillights. The clear base of the LED has a flat spot to mark the anode. With the domed lens pointing toward you, and the anode on the left side (9 o'clock position), bend the legs downward over the edge of 2 stacked credit-cards (or something with similar thickness) to keep the legs about 1.5mm away from the clear LED base. Install the barrel of the lens about 1.5mm away from the surface of the board, using the same flat object. Make sure the LED is aimed perpendicular (90 degrees) to the holes in the board. Solder the legs in place only when the LED is properly aligned. Next, cut the legs off about 2mm away from the board. The legs help with heat dissipation and proper alignment with the light-pipes.

Once the board is later reinstalled in the taillight, the domed lenses must be nestled inside the light pipes and be pointed directly into the pipes with no significant skew. A 9-12V battery can be connected to the taillight connections to check that the LEDs light up. DO NOT connect an LED directly across a battery - you will blow it up or DRASTICALLY shorten its life. The integrated circuit soldered on the board limits the current through the LEDs to exactly 20mA.

[GSB]

Snapping the board back into place is a simple reverse of the extraction method.

A concern to me, was the very bright sparkles of light coming out of the 3 red windows adjacent to the LEDs. A 5mm LED has a bright spot of light visible from the side, and this spot lands right in the center of each window, which may detract from the overall look of the taillight. So, I cut a piece of flexible plastic from a white 1-gallon milk carton, as shown in the photo, to slip in over the windows. This gives a professional, frosted-red look from the outside, and the brightness of the windows now matches the rest of the taillight. Make sure that the plastic is shaped to fit in snugly without slipping around after installation. A dab of silicone in one corner will hold it more permanently.

The taillight casing will need to be properly sealed with silicone or a very reliable adhesive to make it watertight because that portion of the taillight is actually outside the car and fully exposed to water coming from every direction. A tiny hole or crack could be a disaster, allowing dirty water to infiltrate, which would encourage moisture, fungus and electrical malfunction.

Before applying silicone to the plastic casing, use a clean terry-cloth and alcohol to scrub thoroughly around the sealing surfaces to remove every trace of oil or other contaminants. Wipe and/or vacuum any dust or particles inside the casing. Do a dry-run of the reassembly process without silicone to make sure that everything lines up properly and that the taillight works and looks as expected.

The new LEDs are bigger and heavier than the old ones, and they no longer have a plastic mounting block to hold them firmly to the board. The significant vibration and impact in a car will eventually cause the LED solder joints or the thin copper tracks on the board to crack, so it is highly advisable to add a blob of silicone under each LED and around its legs moments before reassembly. Do not get silicone too close to the domed lenses and do not let this silicone cure before reassembling.

Now apply silicone to the mating surfaces of the casing and reassemble while carefully aligning the LEDs into the light pipes. Smooth the silicone proud of the joints and use a gentle clamp (or tape) to hold it all together for 24 hours before installing in the car. Silicone is extremely messy, so have plenty of paper towels handy to clean up as you work.

[GSB]

The results have been fantastic. Now my new taillights look the way they were supposed to look!

[Wolf 335]

Originally Posted by GSB

The results have been fantastic. Now my new taillights look the way they were supposed to look!

Great effort!

Thank you for sharing the proess.

[GSB]

Originally Posted by Wolf 335

Great effort!

Thank you for sharing the process.

You're welcome! I hope it's helpful as more of our lights start failing! Thanks to the OP as well.