Interior lights not working

That unit can pop out handy enough so check in behind for loose connections - next would be to check fuse

Check fuse F29 under the bonnet - do rear seat lights work?

 
Thanks Boydie - rears are also doing the same (flicker but not coming on), and the fuse under the bonnet is fine. Interestingly, they started working when I used it on Saturday but are back to playing silly buggers again now.
 
Bump! Still doing it, occasionally they work for a bit but more often than not they don't! Does anyone know where the lights earth to? Is there any wiring through areas that it might break with age (i.e doors)?