W126 LED taillight project

I wrote this up for one of the forums but it went underappreciated...it is definitely useful however, so it will live in eternity on my blog, woo!

A common criticism of driving an old mercedes (particularly a diesel with a cloud of black smoke behind) is the lack of visibility at night. I can always pick out a w123 or w126 from a distance because of the dimly lit, downward-facing running lights. Stepping on the brakes does not do too much either, unless you are blessed with a third center brake light. With that in mind, I realized that there was a large portion of the w126s taillights that are NOT being used at any given time. There is the inside red lens where the euro fog lights would go (but U.S. versions have nothing) as well as only half of the main red area being used for running lights. Since I have a spare w126 laying in the yard, I took one of the tails off of it to experiment and this writeup is a result of that experimenting. I have a working prototype and will be converting the other taillight as soon as I can run down to the parts store for another LED light. Advantages of this LED light setup:

• Using the ENTIRE tail light area as running lights, therefore increased visibility--meaning running lights are angled towards other drivers and not just the ground as stock is set up
• brighter and truer red color
• much quicker response time compared to normal bulbs
• using the typically blank euro fog lights for additional brake lights - increased visibility
• LEDs last much longer and usually do not have to be replaced as long as they are not subject to varying current
• Its really easy

Disclaimer: I am not responsible for any harm or damage as a result of your following these directions. I am not implying or expressing that these taillights may be street legal in your local area.

Ok, so here is what you need:

- figures 1.1, 1.2: a DOT-approved 3 prong LED taillamp from NAPA, the type that you see on trailers and trucks. Cost about $25 if I remember correctly. Mine was about 3.5" diameter, filling up the whole red area of the tail light
- w126 tail lamp assembly
- soldering iron plus flux, shrink wrap, solder, and bullet-type electrical pins
- some way to cut plastic. Doesn't need to be pretty. I used a dremel with a variety of tips
- super glue
- about 1-2 hours of time

1. Completely disassemble the tail lamp. You'll have to separate the gasket (good time to replace it too), lens assembly, "reflector" assembly, and the metal strip with light sockets.

2. cut out room for the LED lamp in the reflector assembly. This takes some time and patience to get perfectly right. I got it after about an hour of trimming. You have to make sure to take the middle light separator out. Interesting note is that the plastic is crudely painted "reflective" silver. I can't imagine it doing much good in terms of light reflectivity.

3. Eventually get the LED snug in the reflector assembly so that it presses up against the lens/refractors (figures 3.1, 3.2). A couple dabs of super glue to the reflector assembly will make sure it doesn't go anywhere. Secure the screws to the lens, making it all one piece again. A good idea to test out the LED on a car battery for proof of concept (figure 3.3)

4. Wiring! Everybody's favorite thing! Actually it couldn't get ANY easier than this. First off, take either the bulb socket for the running lamp or the taillight and snip the wire off of it. Put that bulb socket in the "blank" space, where the euro fog light would go. The LED bulb I had already had the appropriate connections molded into the plastic: "tail", "ground" and "brake".

Connect and solder:

• black and red wire to the "brake" connector. Solder this to a bullet type connector and plug in. Solder in another wire to the bullet connector (so it will have two coming off of it) and solder the other end to the socket you just popped in the euro fog spot. Having these two in series will trick the car into thinking there is no bulb out (LED resistance is negligible in comparison) and they will light in unison.
• Connect the Green/white wire to the "tail" plug via another bullet-type connector
• Solder the ground wire/bullet anywhere on the metal strip holding the bulb sockets. The whole thing is a ground.

After that is all neatly done you can connect everything back up (figure 4.1)

5. Plug it in and try it out! (Figure 5.1) See the difference--I apologize my camera is NOT good at taking night shots so it is difficult to see. The camera actually makes it look a bit worse than stock but I can guarantee you in person the difference is dramatic. Remember that LEDs produce one wavelength of light and bulbs produce a spectrum, I think that whatever the wavelength is for these LEDs is not well reproduced by my cheap camera whereas the spectrum is sort of a "flood" of light. Anyways, I noticed the normal taillights are not only pointing down and using 1/4 or so of the available space, but they are also amber colored. Using the LEDs brought light to the entire surface including the part FACING drivers behind you, and they light brighter as the brakes are hit. The biggest difference is the added brake light. Originally I used a larger bulb in the socket but it was too bright (figure 5.2). Putting a smaller bulb (like that used in the old running light socket) was perfect.



I will feel much more comfortable cruising around at night in my 300SD now knowing that people behind me will actually know I am there now, and know when I am braking. The addition of a center brake lamp will also compliment the enhanced visibility of this project, that is certainly on the list for me. I hope you guys find this useful!

Figures:
1.1, 1.2: The LED lamp that I used. Typical truck lamp.




Figure 3.1, 3.2: The aftermath of a lot of cutting/trimming



Figure 3.3: proof of concept hooked up to car battery


Figure 4.1: wired and ready for assembly


Figure 5.1 brakes on:


5.2: with the "euro" bulb that was too bright

Big Deezy

Or Lil' Deezy, Deezy F Baby, or Deeez(y) Nuuuts, pretty much any rap reference will do for the name of this next car.  I mentioned in a forum post that my car (Boxy Brown) was rotting away on me and didn't have much life left.  Another member consequently PMed me and let me know he had a rust-free shell available in the area, hell yeah!

Actually getting the car was a stupid and unnecessary adventure. The first time I drive out there (about 90 min-2 hour drive) Boxy really did not approve as the water pump started puking up coolant on the way over.  Naturally, I only notice as I pull in to see the white car I am about to buy.  Luckily, the car was located at a small airport so aircraft techs were there and willing to give me a couple water cooler jugs of water.  I filled each of them (10 gallons I think?) up with water and stuffed rags in the top.  It is amazing I didn't get pulled over on the way back for having thirty gallons of molotov cocktail-looking things buckled into the rear seats.  I limped the car into a street parking spot where I spent the next week out in the cold replacing the water pump after working all day--eventually I fixed it despite only having about 30 minutes of daylight left by the time I could get out there.
Next adventure was the shipping guy.  I used Uship which is a fairly reputable site for finding companies to ship all sorts of large and heavy things across the country.  A few folks bid on my car with the condition of shipping it within 3 days, and I settled on one that had good ratings (this was a Thursday).  I told the seller I'd get the car out of the way on Monday, so three business days or 5 regular days to set up a shipping time.  I call Thursday, no answer...leave voicemail...friday I get an answer but its "We're real busy now can we call you back in a bit?"...no call back...I call Saturday, no answer, call Sunday a couple times and the guy picks up and bitches at me for interrupting his dinner.  Hmm...communication seems to be an issue.  Finally I get it to be picked up on Tuesday after a lot of teeth pulling.  They were supposed to come out by 11 am and pick it up, so I only took a half day from work.  At 12 the guy calls me and tells me he is just getting going from DE, a couple hours away.  Finally at 3, I get a call and he asks "ok how do I get there, I don't trust my GPS" *facepalm*.  I had to give him directions for a place I had only been once before.  He eventually does get there, quite possibly the dumbest guy I've met in person and I begin to question whether my car will reach the 250 miles where I will be storing it...My father (on the receiving end) tells me the car almost fell off the trailer but after blocking traffic on the street for an hour they got it off.  WHEW!  Now I could start working on it!

This summer my project was to take the engine and transmission out of Boxy and put it in the white car (had yet to be named).  I was able to do it in 3 days, what a breeze!  Getting everything else swapped over was a bit more difficult, replacing all the brakes with my new ones from the other car, an entire interior, climate control, etc.  It was a fun project, nothing is easier to work on than these old Mercedes, period.  Only a week and a half ago, I got my temporary tag from teh DMV and took it out for a maiden voyage.  Even after 211k, the chassis is without a squeak or rattle!  The only point of concern now is a rust spot below the battery, which is a tough location due to the swaybar support bracket about 1" away.  It appears a mouse lived in that little spot and blocked the drain hole, letting water build up.

 Eventually I'm going to have to get rid of one of my MBs but its going to be tough.  Since the DMV takes months to mail titles I guess I do have quite a bit of time to enjoy this one, though I could use the money and a new project. 

Boxy Brown

Being an auto blog I obviously need to introduce my awesome rides.  Boxy would be the first of the Mercedes that really got me into these old heaps of metal.  It all began one day back in December 2008....

I was visiting my family in New England as I usually do for the holidays and was simply driving a nice scenic road in my Dodge Stealth (RIP!).  At this point, I was putting on about 15,000 miles a year on my car and hauling lots of stuff back and forth being in school.  The Stealth was just not a practical car though I loved it much and it was a lot of fun.  On this cold winter day, parked outside of a  very old (1700-1800s) antique and crafts store was a lonely looking turd of a 300SD.  It had massively faded paint, a bit of rust behind one of the rear wheels, and used to be dark brown with palomino interior.  The very next day I gave the guy a call and he met me outside the store, putting on the sales pitch.  He started the car and as soon as I heard the diesel clacking away in 15 degrees, I knew this car was for me.  I bought it the very next day for less than $1000.
   Driving home was an extremely scary adventure.  Since the DMV did not require inspections, I literally walked in the DMV with nothing and walked out with plates and an empty wallet.  My father drove with me to pick up the car and unfortunately by the time I got the plates on, it was rush hour.  It took me all of about 100 feet to realize only one front caliper was working.  I DID make it home about an hour later and after numerous angry rush hour motorists expressed their distaste for my slow, smoking brown slug.  The transmission flared VERY badly in the 1-2 shift and 3-4 shifts, and slipped pretty badly as well. 
   It sat in the driveway for a couple months while I was in school, since I didn't have a chance to work on it while living 250 miles away.  I saved up and bought all the parts I needed, most notably an entire braking system from the booster to the tires.  Early in the summer I put it all together, cleaned out the ALDA line, replaced the B2 piston/bushing in the trans, cleaned the valvebody, cleaned the fuel tank, replaced normal stuff like glow plugs, filters, etc.  By July I had a daily driver!  Not too bad for a diesel noob like me, I learned a LOT from Boxy. 
   Boxy had some other "mods" too, obviously the EGR valve was immediately blocked off, I switched to LED lighting on the inside, and put in a kickin' stereo system.  To accomodate 6x9's in the back, I fabricated a new rear deck and upholstered it in matching vinyl (well, the best I could to a fading pinkamino interior). 
  I should explain the name...Boxy brown is a character from Aqua Teen Hunger Force (yeah yeah, I know...)

I see the resemblance quite clearly myself.....


Anyways, Boxy served me well for over a year and only failed to start once outside the office in -6*F because the battery couldn't put out enough juice to crank it.  I put on about 15,000 boomin' miles until rust got the best of him.  When I bought the car I didn't realize the rust was that bad....turns out there was a ton of hidden rot at all of the jack points and the salt ate away at the trunk floor to the point where you could see straight through it!  Despite having a healthy engine and transmission, Boxy was dying quickly and succumbing to the rust.

So come almost exactly a year later, a fellow on one of the forums I frequent offers a Texas 300SD shell (no trans/engine, no interior) for next to nothing.  The saga continues....

Introducing myself

Welcome to the ranting of an over-zealous Mercedes owner and DIYer.  Seems like every day is a new adventure with these cars, working on them and driving them.  Many of my posts will DIY related (anticipate much cursing after mishaps) but anything surrounding the automotive world, specifically MBs might appear here.  Just to make it clear I have absolutely no affiliation with Daimler Mercedes Benz, MBUSA, MBNA.  I'm just an owner and fan tryin' to live day by day.