Ok, still looking for some help. Went ahead and replaced the actuators (one was bad and stayed engaged all the time) turns out it was broken in half. Anyway the primary problem remains. Occational grinding caused by power to solenoid being cut.
So, I bypassed the solenoid by connecting the vacuum lines direct; which effectively means I'll have to reconnect it for 4WD.
At any rate, I still have the problem. Does anyone have a wiring diagram for this? Would be very appreciated...