My S2 still will not work on the interior fan.

I have of course taken the plug off to the actual blower under the bonnet but no power. There is no power behind the dash switch on the speed variator either.
Where do I go to now to check for power and do they have a relay somewhere under the dash?
Shame as it's the only thing that lets my grey RS down - never has worked!
Thanks for any help.

Paul