I have a 99 blazer LT with the automatic transfer case. Recently when I try to go from 4hi to 2hi the switch appears to do nothing. The 2hi doesn't blink like it is trying to switch. It doesn't acknowledge in any way that I hit the button. If I turn off the truck and then restart it I can hit 2hi while the instrument panel is flashing and it will switch to 2hi. I think possibly it is the switch that is failing. Please let me know your thoughts