cant get the scanner to communicate with the 4x4 mod on a 2011 ford ranger the dash lights are on any ideas where to start

 I checked the power and grounds I have power to the module checked the fuses but I plug it back in no power to the switch 

 thanks I over looked a fuse that was pulled and didn't even know there was supposed to be there thanks for your help. put the fuse back in and the 4x4 works great no other codes or blown fuses.