my 2001 chevy s10 blazer 4x4 will not engage. I push 4 hi or auto4wd it flashes for about 30 secs or so and then turns off and goes back to 2 hi, and when I push 4 lo it flashes and I fill and hear a sound like it is engaging but the light stays flashing instead of staying lit with no flashing. what could the problem be, if anybody could help please get back to me.
Croley