I have a 1999 silverado z71 with push button 4x4! A few months ago I was trying to put it into 4x4 and the lights flashed then all lights went off like it lost all power!! I haven't been able to Figure out the problem since! I was told it could be the 4x4 control module behind the dash! I bought a new one but still didn't fix my problem!! anyone have any ideas??