where did you plug the Wii into? tv? dvd player? dvr?
whichever one you plugged it into, you have to find it in the aux/input. all inputs are labeled (a/v in 1, av in 2, av in front, ect...)
if you plugged it into the dvd player or the dvr, then it has to be on in order to work. the aux on that device must be selected properly also.
I.E. if plugged into dvd player
tv must be set for the dvd player input
the dvd player must be set for the aux input