I applied vacuum to both sides of the actuator. It moves the rod in and holds position until vacuum released. The other port holds the rod out. Cannot push it back in. Checked the vacuum lines. No leaks. Checked the solenoids. They both hold vacuum. Not sure I checked them right. I guess the next step is to check the harness and relays.

 

I applied vacuum to both sides of the actuator. It moves the rod in and holds position until vacuum released. The other port holds the rod out. Cannot push it back in. Checked the vacuum lines. No leaks. Checked the solenoids. They both hold vacuum. Not sure I checked them right. I guess the next step is to check the harness and relays.

 

you might be OK on the front end and solenoids... if it did "electrically" jump into 4 x 4 , that had to start at the transfer case motor. Like Bluegrass said, it could be an oddball ground as the power is available all the time.. New motor - set on the ground and switch it in and out a dozen times.. wiggle wires, flex, kick... see if you can make it repeat the "jump into 4 x 4" by itself ..........After several tries, if all is well, install the motor , road test, hope for the best.

 

Hooked up new motor, shifted from 2wd,4wd,4lo several times motor worked smoothly. Relays clicked in and out as normal. Installed motor on transfer case and operated from 2 to 4hi several times. Then selected 4lo. Checked the actuator several times to make sure it was working properly, backed it out and the axle disengaged as it is supposed to. Wires look good, still flexible and intact. Tried wiggling the harness no change. Checked at negative battery cable, not showing any major draw there. Also doesn't seem to be any leaking around the area of the GEM. Not real sure what happened to cause it to engage. Kinda spooky. Will stick to the back roads for a few days to see how she acts before I get on the freeway and up to speed. Maybe after being parked for 7 years it was just corroded and shorted out. I do appreciate al of your input. Thanks