Well I've replaced the actuator, cable , and vacuum switch. Still not engaging the actuator. I know it's prolly the vacuum system but I don't know where to start.

 

did you find any trans fluid in your vacuum lines

 

I did and I blew them out

 

do you hear the transfer case engage when you push the 4 wheel button? if so you may have a leak in the line going to the actuator

 

I know the feeling, the 4 wheel drive system on these trucks are so finiky. After about 6 months of trying to figuer out what was wrong with mine it was 3 different problems. 1 my vaccum hose was disconnected from my actuator, 2 my vaccum switch on the tcase was seized, i then replaced the push buttom 4x4 switch and the mccm 4x4 computer thing. Then i gave up for a few month's until winter came then out of no where I started slamming a hammer on the Encoder motor on the tcase then it started working. It must of been seized up or something and hasn't failed me now in over a year and a half.

 

If you have ATF in any vacuum line, then a vacuum switch on the T-case is bad and need replacement.

Check for vacuum at the actuator under the battery. If not, then just follow the line. It goes to the vacuum switch. Check for vacuum here. If not, continue following the line.
Next stop is a T fitting. Check for vacuum on these....and so on. Vacuum source is the engine.

Vacuum also goes to the T-case switch.

The likely problem is a rotten vacuum line. Plan on replacing all of them.

 

Thanks. I'm just gonna run new lines.

 

Good luck hope this is it. Can be a PIA

 

What is a PIA?

 

Pain in the ***