Why is my 4 wheel drive not working no lights on push button 2004 gmc z71

SOURCE: Front drive, 4 Wheel drive won't engage

Check the switch on the transfercase remove the vacume lines if there is oil in them the switch has to be replaced and the lines should be cleaned out you should also check under the battery tray to make sure the boot is not ripped that controls the leaver to engage the front axel

SOURCE: 4x4 will not engage in 96 gmc yukon

I just fixed a friend of mines 96 yukon...shift to neutral press 4H and u can hear the actuator make noise (we even replaced it with a new one his idea and the same thing happen as old one), so as he hit the switch for 4H i layed under it (on 4 jack stands) and I could hear the motor on the transfer case make a loud noise (well thats working) and before all this I asked him did u check all your fuses (he said guarnteed to be all good) one night it was bothering me so i looked through the owner manual for the yukon and in the fuse box on driver side by the door there are (2) fuse for the 4wheel drive unit,pull one of the fuses good...pulled the other one and it was blown put in a new fuse and it works like brand new..pull fuse for anything that has to do with 4 wheel drive componants,

SOURCE: 4x4 push button is not working about how much does

This is something you can do yourself if you have ever worked on a vehicle before. The part you need is called a front drive actuator valve. It costs about $ 50.00, GM part # 15165891.
Here is some more infor about it:

Main 4wd Components:
TCCM - Transfer Case Control Module - Located behind the glove box. This is the electronic 'brains' behind the shifting.
Switch - The push button switch in the dash - driver input/indicator.
Encoder Motor - Located on the transfer case - This is what actually shifts the transfer case, and tells the TCCM what position it is in.
Vacuum Switch - Also located on the transfer case - This is what sends vacuum to the vacuum actuator (see below) when the transfer care is in 4HI or 4LO.
Vacuum Actuator - Located under the battery tray - This is what engages or disengages the front driveshaft.
Front Axle Switch - Located on the front axle - This is what tells the TCCM when the front axle is engaged.

If you want to try and replace it yourself, please let me know how it goes.

SOURCE: 2004 chevy silverado 1500 4 wheel drive wont work..

try selecting from nutreul or less then 3km

SOURCE: Steering Wheel Lights not working

they just pop out small screw driver pry out