2001 Blazer will switch in to 4wd and back to 2wd when I push the button to do so, and the light stops flashing which leads me to believe it gets to 4 and back to 2. When in 4wd, I hear a ticking noise from front passenger side, increases with speed, like a playing card in your bike wheel spokes. I've tried several times, same result. Will not try again unless I get stuck, dont want to cause more damage. Any ideas what to suspect or check?
Thank You!!

 

Your front axle isn't engaging all the way.

This thread talks about that:
4wd Front Axle Clicking When in 2HI - Goes Away when in 4HI/4LO

 

Swartlkk, thanks for all the help. Much more than I ever could have asked for, will investigate asap.

 

check all the fluid levels. the front differential fluid and transfer case fluids but kinda sound like the axle engaging problem...