My fix for the rear tail-light issue
 

After suffering with this problem and doing all the usual fixes but nothing seems to really be a good fix , the merc bulb holder fix gave me an idea so here's what I did.

remove your bulb holders and carefully remove the pins and solder wires to them and refit you should end with holders looking like this in picture 1 , then you'll need a pair of rear lights to remove the metal tracks from picture 3 ,you need to leave the tracks in your original lights as this is what keeps the holders in , trim these tracks down so you end up with a pair of sockets like in picture 4 , remove the pins and put a bend in them as per picture 5 , i also trimmed the sockets down as can be seen in picture 6 , then solder the wires to the pins i refitted the holders in the lights to get an idea of wire length make sure you observe how pins where connected in the light as the pre face lift has 5 pins and facelift 4 pins , wrap with some loom tape little bit of epoxy glue to keep the pins in and they you go some plug in looms and bye bye tail light issues , only thing to check is you get all the earths on the holders correct when you put the holders back in your lights.

Even better you could have just put a few patches of solder onto the original bulb (holder) contact points. There should be some instructions and pics somewhere on here for that ;)

Seems that's just a temp fix been there done that seems you just play chase the fault , the issue is you get a hot spot between the holder and its contact point so you fix the light then the fault transfers to the holder , hence why I decided to do what I did.

Nice work. :thumbup:

Any fix that sorts these sodding tail-lights is a good fix! ;)

Nice work! Thanks for sharing the good job.

good to see you back! x5 is going ....20 years old in dec this year......niggly annoying issues but touch wood still going

FWIW, I've sorted my LCI tails lights with the usual solder fix BUT it turns out it works MUCH better if you apply solder to BOTH the socket base (steel plate) AND the bulb holder pins. I used silver solder in both locations and (touch wood) have never seen the bad contact issue return. :thumbup:

I did mine many years ago (prob more than 10) shortly after I bought the vehicle at about 192k km. I remember doing a nice job using acid core leaded solder on the metal strips but I don't think I put any solder on the sockets, anyway I would have used contact grease on everything and have never had a problem since (470k km now.) I had similar crazy contact problems with the rear bulbs on the E70 as well when I bought that a few years ago but I think just some bending and contact grease is all I did for those and all has been good since on those too! so far---- ;)

I had considered doing something similar to what dazzasgotav8 (Darryl?) has done above, soldering tails onto the contacts of the bulb holders, but then soldering the other ends to the appropriate metal back-plane locations.

The only concern I had was around the ease of changing lamps - it could get messy with wires (tails) everywhere. dazzasgotav8's solution above deals to that nicely! :thumbup:

It's a shame that they didn't spend 5 seconds and a few cents worth of grease at the factory. I'm pretty sure my E30 (still built in Germany) had greased bulb contacts (and probably better contact material) ;) Anyway with PWM and quality bulbs they last almost forever :)