The "Service 4WD" light came on my 04 Chevy Silverado Z71. I was stuck on some snow and pushed the 4WD button. I was dumb and pushed the 2WD button when I was unstuck and the light came on. Now I can't use 4WD and I need it. Can someone tell me how to fix it? I heard about resetting it in the fuse box, but I don't want to do anything to screw up my truck. Thanks! Merry Christmas!