I have just bought a 2008 520d touring which had what was thought to be a simple bulb failure on the rh no. plate light!
Not so simple! Bulb OK but I discovered the lh one only worked when the tailgate was closed, about halfway up it also stopped.
I rigged up a simple feed from the working light to the other until I could get it to a dealer for investigation.Both lights now worked when the tailgate was closed but rh light failure warning signal continued to appear.
Their diagnosis was 3 hours at a cost of £475 !! to repair as the headlining would have to come down. I told them to return it so I could try to repair it myself, however on return not only did neither no. plate work in any tailgate position but the rh fog and reversing lights didnt work nor did the main tailgate release. ( still opens OK with remote or drivers switch)
Dealer refuses to acknowledge that anything they did caused the additional failures and blame the temporary feed despite the fact that this worked perfectly satisfactorily for several days.
I have stripped out the tailgate lining and the loom covers where they run alongside the hinges, also dropped the rear of the headlining as far as the speakers but all looks OK.
Logically the most likely place for wiring damage is where the loom flexes with the door but this looks fine.
Does anyone have any other ideas where to look? Is there a connector somewhere further into the headlining which is vulnerable?
All suggestions welcome.
Thanks

 

no advice to offer, but this looks like a promising thread.
pls let us know when you find the culprit.

 

https://5series.net/forums/topic/727...s-replacement/

check this one, prob. the same problem

 

this might help. found this when looking for an intermittent reversing light failure

 

You have the classic case of broken wires in the tailgate hinge, search on this forum for the various discussions and fixes to the problem.

 

Thanks. I have seen various suggestions and I will pursue.
Regards

 

 

Now that is a handy PDF for future reference, thanks

 

I know this has probably nothing to do with your problem but i had similar issue with lights on the rear, it was my electronic opening tailgate which had pulled cables and broke them in the roof lining on the right hand side, i also had remote locking issues as the sensor for the remote is in the rear spoiler! i pulled back the roof lining from the boot and saw several broken wires, when the boot was closed the lights and locking worked sometimes due to the wires touching again.

 

Thanks for the comments.
I spent an afternoon repairing the wiring damage and it is just as reported in the various threads. The most common problem area seems to be the furthest right conduit which contains cabling for rear right lighting and main tailgate lock among other things.
I suggest anyone doing this job considers replacing a longer piece connecting into the loom where it continues down alongside the tailgate edging (black plastic piece to be removed via 4 screws and releasing the seal along that side)This makes one of the series of connectons easier.
As only! 3 wires were broken and 2 had damaged insulation I did not cut them all but on reflection it might be easier to cut all and rejoin.
I got some scrap loom from a breaker and used appropriate thicknesses to fix.I used solder although the reccomended BMW connectors look good but need a crimping tool to use.
The new thicker loom now doesn't fit as well into the 2 piece metal conduit but it is OK.
Note - in the excellent pdf document available in this forum it states thet a plastic stud in the hinge has to be removed to release the half of the conduit. This was not so in my car as the conduit was narrower at this point and could easily be levered past this stud. I cant see where the source of the problem lies so I expect to have to repeat the performance sometime if I keep the car for a long time.
Thanks again to all respondents for the advice and encouragement.