2005 500 4x4 not working.

[250ex 2010]

My dad has a 2005 500 sportsman and the 4x4 has quit working. When you switch it into 4x4 it doesnt do anything and the light on the cluster doesnt come on either. I checked the swith on the handle bars and it is good. I was wondering if this is common and what it could be. I am not very fimilar with these 4x4's.

thanks.