Gamecube controllers not working?

Hey every1 I was wondering if there was something special you had to do to get the gamecube controllers to work? I have 2 wireless and 1 wired and I put them in the ports, turn on the wii and there's no cursor or anything. I was wondering if that's how you do it or if there's something in settings or what, maybe my gamecube ports don't work? I got it used and never had any probs with it until now, thanks for any responses :)

Exactly ^^

Also, not all wii games can be played with GC controllers