cruisertom

2002 4runner with ABS and 4wd push button on side of tcase shifter. Installed new gears in it today for a friend and took it out for a test drive and now when he pushes the 4wd button it goes into neutral. We double checked all the connections. There was one electrical connection that could have possibly been damaged, but I can't find a wiring diagram to look and see what is going on to try and diagnose. I think it is electrical but can't find anything on the web. Does anyone have a schematic of the 4wd and front axle engaging system that I can look at? Thanks, for any help.