The permanent taillight fix

[wpoll]

Originally Posted by ehummelman

OK, after lots of reading on the solder fix, I found this thread and bought the MB kit. Put it in and the bulb still doesn't light. Still have errors on the dash. What could I have done wrong? This is on an 05 4.4 if it matters. The weird thing is that I am getting "check tail lights" and "check brake lights" errors but only the bottom light is out. The middle one works fine.

How did you wired the MB kit into the BMW loom? As described here by disconnecting the original BMW wiring?

[ehummelman]

Yes, exactly as described in that link with one exception. Not sure if they changed the connectors but the BMW pin on the black/blue wire does not fit into the MB socket, so I just used a 2 pin Delphi connector to splice the black/blue to the red (power) and the green to the brown (ground). I'm still getting nothing and the errors in the dash. I just bought another tail light housing off ebay because I'm so sick of it not working.

[wpoll]

Have you verified that you have power on the blue/black and red wire splice (or on the lamp socket)? Sounds like the ground wire should be OK, although most folk seem to use a chassis earth rather than a wired return path. I prefer the wire return path myself too.

If there is a voltage between the blue/black and red splice and your brown wire return path then there has to be a fault in either the socket or the lamp - maybe the socket is for a different model lamp or something (staggered bayonet)?

[ehummelman]

I haven't busted out the multimeter, but now I will just to make sure that socket is actually getting the signal to light up. Maybe it's the LCM, I don't know. Oh, and I must not have explained it well, but the ground circuit is to the chassis. The MB socket has a brown ground wire that connects to a green ground wire at the connector. The green then goes to the housing mount stud. If you look at the pictures of the MB part it will make more sense. Not sure why they used 2 different colors but they did.

[thrillcat]

What did you ever find out about this, with the 3-bulb lamp? Re-reading the original posts, it almost sounds like perhaps the 3.0 models only have a single taillight and the reverse bulb. What is the process for those of us with two taillights and a reverse bulb?

[ehummelman]

Sorry this probably won't help you, but I ended up ditching the MB parts and just fixed my housing via the epoxy method explained elsewhere. There's an official BMW instruction document somewhere that explains how to do it. You basically build up the plastic support under the metal circuit that shorts and burns out so that you have firm contact. I also soldered the burn mark on mine while it was out. No problems now. Yet another intentionally designed to fail part. I think I've hit almost all of them now from the door handles to the alternator bracket o-ring to the final stage unit to the brittle cracked headlight wiring... you get the point. They're a bitch sometimes, but I still love mine, it's a hell of a vehicle.

[thrillcat]

Thanks for posting back. I soldered mine up last week, too, but if I can figure out wiring in the MB parts I will. But until I hear back on the wiring, I guess I'll hope this sticks.

[Russianblue]

For posterity I am posting a youtube video which, while for a Mercedes ML I believe, will go a LONG helping folks visualize what's going on here.

I was lucky enough to find a 2005 Xer with 70k miles in 2017 and am just now approaching 90k, so this site will remain a good resource for me for sure!

https://youtu.be/e40e_8_4N_A

I'm also going to cross-post in the other major thread on this topic.

https://xoutpost.com/bmw-sav-forums/...t-fix-diy.html

[Russianblue]

Originally Posted by ehummelman

Not sure if they changed the connectors but the BMW pin on the black/blue wire does not fit into the MB socket, so I just used a 2 pin Delphi connector to splice the black/blue to the red (power) and the green to the brown (ground).

ditto on this no-fit for my 2005 3.0i. I have some weatherpaks I will use too but I need to order some of the crimps for smaller gauge wire and will use this same method. makes the $40 of mercedes parts kind of expensive though since you aren't gonna use anything but the bulb socket. I might just solder/rig it up to a spare BMW socket if I hadn't ordered the Benz stuff already.