I take it all back.
Could have sworn I'd seen one in the back. (ahh, may have been a V70 estate thinking about it)
Anyway, I hope Volvo make better scuttle drains than VX 
Kevin
Possibly not...

The fuse is fine (it's fuse 35 and it's 10A in case you were wondering), swapping it around with another good fuse seems to resolve the problem, so i am thinking of bad contact... and considering the location of the fuse box in the scuttle and the pine tree rubbish all around it, the base of the fusebox is probably corroded... I am tempted to take it out and give it a permanenet fix but keep reminding myself that (a) I am on holiday and (b) it is not even my car!
Anyway the dashboard illumination is working (for now) so thanks to all and especially to Spongebob.
The other problem is that courtesy lights are not working, but unlike my initial thought this is not a fuse problem, instead the switch in the roof console is physically broken so new roof console is needed. Does anyone know of any good Volvo scrappies in Italy? Nooooo! I'm on holiday!!!!