4wd selector switch isn't coming on when you crank it

https://www.autogenius.info/chevrolet-silverado-2003-2006-fuse-box-diagram/ Using the diagram link above - double check fuses - one is inside cabin the other is under hood - I always liked to test em all using a 12 volt test light - ya never know when a circuit FEED fuse is the problem - a fuse feeding other fuses. That test takes about 10 minutes tops. Good luck!