G'day, I have a 99 Scrambler 400 and I am a newbie when it coming to these ATV's.
Last weekend I got stuck in some ruts and when I went to engage the push button
4wd nothing happened. Can you guys give me some idea's where to start looking for
this problems. Thanks
Adam

 

I've seen this a lot in here, try the search first, you may find the answers quicker (and see how well they helped others since not all suggestions are good ones) It could be a loose wire going to the front wheels or mud could have gotten in there. I know I have seen a lot of other reasons for this to stop working so if you don't see any loose wires, or if it looks clean I'd do a search in here.

 

I had that problem to check your battery connections that is what it was for me my battery terminal fell off and it wasn't getting electric to the hubs to kick them in. if that doesn't work check all your wires going to your hub.