I have vacuum to the actuator under the battery and it pulls the engaging cable but not quite far enough. When engaging with battery removed (but running) the actuator pulls but doesn't engage, when i pull the cable .5 inch farther it engages the front axle.

Would a bad transfer Case Vacuum Switch cause this?

 

From all the videos I've recently watched on the subject, that sounds like the problem. I had a bunch of dry rotted vacuum lines at the top of the engine compartment right in front of the drivers side. but i still need to test my actuator, but will probably need to replace the switch.

 

I replaced a bunch of vacuum lines under the hood and figured this was the last remaining problem. I can't reach my hands up in there SO I'm going to cut a hole above it in the floor with a hole saw to get easier access to it. I'll let you know if this was the problem.

 

Do you have the 3 button switch in the dash or the 4 button one? from what I've researched here, the 3 button switch has the vacuum switch on the xfer case on the drivers side. The 4 button switch has a solenoid mounted under the hood in the middle top firewall area....

 

STOP, don't cut it. you can reach it from underneath.
It's 7/8", Should take only 2 min.

 

already hole sawed it and replace. You can reach it, but barely. I dont have carpet in my blazer so it was no big deal to cut and replace. It didnt solve my lack of vacuum issue though. might just go the posi lock route now.

 

posi lock kit ordered