[Proghound]

Doesn't look like any of the C70 regulars on here have had this one.

I'm assuming you've had the bulbs out and checked them? And you've found and checked the fuse? If so, and the 12v socket and the roof raise button which are also on that panel are working, I'd guess whatever switch is faulty that's activated when the boot is open.

I can't see an obvious switch on a quick look around the boot opening on mine, although thinking about it, it may be a microswitch in the lock itself. You could try lubricating inside the lock with WD40 through a spray-straw, that's a trick that works with the microswitches in the door locks when they open to the first stage on their own.

Short of that I'm out of ideas I'm afraid, but you could use the forum search to see if any of the S40/V50/C30 guys have had anything similar.

Good luck and do post back if you get a resolution.