Hi there and velsome to beoworld.
I got a WII connected to my Beovision MX6000 so it should work. Connect it to scart 1 socket, in the menue of the beovision specify that scart 1 is V.tape, and then press v.tape.
The manual of the Beovision 3 is avalible on this site if you upgrade to gold or silver membership and at the same time support the site.
Best regards
Christian