Need help solving my 4x4 problem

[DerekG359]

Hi I have a 99 GMC Sierra and the 4x4 only engages occasionally. and I've looked online it looks like a lot of them have this problem but there were a lot of different solutions. How do i get to the source of the problem? It only works sometimes and when it does it took a lot to engage it. I have to keep pushing the button and sometimes it finally works or it just doesn't work at all

[DerekG359]

Okay I just got it in 4wd now it won't go back into 2 hi

[Motodox]

Sounds like that actuator on the transfer case needs replaced. Never had a problem with mine but I'm pretty sure it's a common replacement part.

[gmtech4]

Okay I just got it in 4wd now it won't go back into 2 hi

Switches are common and cheaper than an actuator

 

Scanning it will get you closer than this absolute guessing