wont stay in 4wd
 

Ok, finally got my truck to kick out of 4w high lock, by backing up and turning the wheel in neutral, but now it will not stay in 4wd, after hitting a small bump in the road, it kicks back into 4 wheel high lock. So is it an electrical problem, wiring, or?

Sounds like either the wires going to the transfer case actuator are loose or its the t case actuator itself? Crawl under and check to see if the connector looks tight. Jiggle the wires and see if that changes the t case mode. Also look for frayed wires, worn insulation, etc. If it's the t case actuator its an easy R&R.

where exactly am I looking? I am real familiar with this system yet...is it on passenger side or driver side, and what exactly am I looking for? sorry, bit of a noob

This is a great photo of what you are loooking for

Hummer H3 Borg Warner Transfercase Photo 3

If it were a wire or voltage problem it seems like the lights would come on.
If it does it by itself it sounds like a break inside,the locking mechanism.
The lock sleeve must move,by itself? No fork,broken fork.
Bad wires could not activate the motor unless told to by the control
computer. The motor is turned off after moving to its proper position.

Mine was doing basically the same thing. It ended up being the fork in the transfer case. What year is yours?

When asking these questions, YEAR and MODEL are important.

I think the only difference is the low range gear ratio and the ones with the plastic fork. The gear ratio should not matter.
It could be a metal fork broken.

It's a 2006, wouldnt the fork throw a code or no? Took it to shop, they think it's the switch inside?

Not sure what you were getting at?????

Years and models always matter. If somebody is gonna ask for help with a problem and expect an answer beyond a wild guess, then they should add the extra keystrokes to include year and model.

Year 06 and early 07s came with the plastic T Case fork.

Year and model matter as to which T Case actuator was used, and which TCCM was used, both of which can lead to the OP's problem, some of which were more problematic than others. Since the OP still hasn't supplied model, I'm not gonna bother........ let him figure it out.