4wd switch problem

switch lights up momentarily when key is turned on. no lights or sound at all when pushed
I tested fuse OK .tried to disconect battery no help .Change switch module from different jimmy same .My switch work on other car ,so I pyt it back
Any advice on what I should do next? Thanks!

Check the 4x4 switch relay.

Transfer Case Module...they are defective on this trucks. See MSN Auto's Reliability Ratings.

This is not switch relay .
I tested T/case Shift Control module -it`s deffective 305$ from the GM
Easy to replase ,take the buttom passanger side panel (no tools needed) you will see module #15741322
Thanks JimmyGold

Hey Sergeia,

PLEASE DO NOT GET IT FROM GM! GO TO GMPARTSDIRECT.COM!!! They have it for $174. That's where I got mine last year. Or you can try a junkyard if you want a cheap used one. Install is EASY!

I get it from ebay for 70$
Thanks