Gen II, what is this connector?

Long story short, I'm having 4wd issues. I'm still reading the forums to see if my question hasn't already been answered. In the mean time, what is this connector? Its on or near the front diff / axle.

 

4wd, Connector goes to the diff actuator that connects your axle to the driven gears. (ADD.... Automatic Disconnecting Differential)

Don't unplug it! It might be the only thing holding your rusty pile together

 

Jeebus....
Wd40 and a brillo pad
Then use penephite on all bare metal.

 

Okay. Does anybody know what the voltages should be going to that connector? Should they change based on 2wd / 4hi / 4lo? Common sense says yes but please confirm.