C5 interior lights

[GiveMeABreak]

Ok, so I've sent you an email with 3 wiring diagrams for the interior lights and the link to the Wiki where I've put many of the codes together.

Hopefully this will help you check the earths and the wires. I didn't ask as to whether the boot / tailgate interior lights are also working as expected when the tailgate is opened? Knowing how bad the wiring is at the rear,I'm wondering if a break here will affect the lighting on the interior lights too.... they are linked together.

[wheeler]

The shunt is actually for when the car is in transit/storage to stop the battery going flat. When the shunt is removed or put in the parking position (there are a few variances in different BSI types) it stops certain things that run off the battery operating. This is how they leave the factory & the shunt is inserted/swapped when it gets PDI’ed.
Showroom mode is slightly different, the BSI can be put in showroom mode but for it to work correctly it needs to be used with a special showroom harness which allows certain things to work even if it goes into eco mode & can allow a charger to be connected.
I went to view a C5 that someone on here was selling a few years ago that he listed as having a fault where the car instantly went into eco mode when switching the ignition off plus a few other little things so i took my Lexia along, i never bought the car (had a power steering pipe leaking) but i sorted the problem while i was there, the BSI was in showroom mode, just switched it back into customer mode. The guy had bought it with this problem too & had never managed to get it sorted.
I agree this needs a look at the wiring diagram to proceed.

[GiveMeABreak]

Yes the point I’m making is that the shunt position is not going to be the cause of the interior light not coming on. The procedure for showroom mode does involve removing the shunt fuse and connecting the harness amongst other long winded an irrelevant processes that would take a page to fill, suffice it to say I’ll likely bet it’s a wiring or earthing issue.