I have a 2000 with the 4 button 4wd. Checked the actuator under the battery and it did move back and forth.
the first time I put it in 4wd this year I heard a popping noise like something was slipping out of joint. It occurred every once in a while, so I took out it off 4wd. Then a few days later it snowed. I got stuck in snow, so i put it back in 4wd, and she ground like a chain was slipping.
Works great in 2wd, but 4wd no. Is it the transfer case chain? What else could it be. Any help would be appreciated before more snow comes!!

 

Welcome to the forum. The actuator under battery just lets the front differential engage so you can use 4x4. The sound you hear more than likely the range hub or worn shift fork. Could also be the encoder for the shift motor is not timed correctly from failing. Do you have any lights flashing on 4x4 switch?
Brad

 

Lights are not flashing. It goes from 2 to 4 back to 2 to with no lights flashing. I hear the solenoid activating. But when I drive I get the noises like something is slipping or popping. Everything is good in 2wd though.

 

Im thinking it's the transfer case chain slipping. Any thoughts?

 

Very unlikely a chain slipping. If the chain is loose enough to slip it would rub a hole in the case. Still needs to come out and disassembled for proper diagnosis. Not going to be repaired installed. Good luck
Brad

 

If i read right, put the blazer up on blocks, Start it and try to turn the front passenger side tire, it should turn. When i lock in 4wd high the tire should not be able to turn, correct??