I did have a search for this but found nothing relevant, when i open the tailgate the lights in the boot area don't come on, but they do when i open the glass, also the red light on the tailgate has never come on, is this supposed to happen, if not whats the problem? is it a symptom of the tailgate wiring loom problem?
Thanks.

 

yes they go on. Probably the switch which detects that boot is open doesn't work. Not sure where it is

 

Ok i will have a look for it, thanks.

 

Bringing an old thread back to life;

Did you figure that one out?
I've got the exact same issue...

 

No, I couldn't find the switch, gave up and moved onto the next issue..

 

I dont suppose anyone knows where the switch is in the tailgate that activates the boot interior lights, do they, i would be very interested if they did, i have looked on Realoem but no joy.

 

Actually, I also don't know, but in a matter of deduction, I know that there is no classical switch. This is similar as in the doors, older cars had these regular push switches but the E61 doesn't have them.

1) Either it gets the signal from the lock: Try to open the trunk and manually (using a screwdriver) push it into the lock in the tailgate and simulate a lock. If the lights go off, then it's in the lock itself.

2) Second thing is the lock in the trunk itself where the lock from the tailgate goes into. If you have an auto tailgate, it is a turning lock which by turning locks the tailgate. Try to check cables in the vicinity of the trunk lock part.

3) If you have an auto-tailgate, then there is an magnetic actuator in the left hydraulic arm, once the plastic cover is removed, the cable going into it is visible.

4) There is also the possibility that the electric lock, either from the tailgate (most probably) or the trunk part of the lock gives a signal to a unit that gives the signal to another unit to switch on/off the lights.

That is it, try to find it by eliminating the possible locations.

edit: Just checked it, and when the tailgate is open - the lights are one - I put a screwdriver into the tailgate lock and put it into lock while open and the lights switch off. So, the lock on the tailgate has the switch. The second switch is in the glass tailgate; when you open the glass tailgate, the light also switches on. So it is possibility 1) from the list ;-)