1999 NBS 4x4 won't engage front axle

[Nunya Biznuss]

I have a 1999 Chevy Silverado (New Body Style) 4x4 that will not engage the front axle when shifted, via the floor shifter, into 4 wheel drive.  I have taken the actuator off the front axle  and connected it to a different truck.  It works properly.  The 4x4 system worked properly until the truck sat for a year.  Now, the front axle actuator won't engage.  I disconnected the wire from the actuator and found 12 volts on one of the pins and nothing changes on any of the pins when the 4x4 lever is moved.  The wire that connects to the sensor on the transfer case has about 10 volts on the center pin and another pin has continuity to ground.  I've even, just for good measure and no results, taken the ground off the cab under the drivers side door and shined up all of those surfaces and put it back on, nothing.  Also, the battery has been disconnected for several hours so the computer would've been reset.  I'm at a loss at this point.

 

Any suggestions as to the cause of such a problem?

[asilverblazer]

12 hours ago, Nunya Biznuss said:

I have a 1999 Chevy Silverado (New Body Style) 4x4 that will not engage the front axle when shifted, via the floor shifter, into 4 wheel drive.  I have taken the actuator off the front axle  and connected it to a different truck.  It works properly.  The 4x4 system worked properly until the truck sat for a year.  Now, the front axle actuator won't engage.  I disconnected the wire from the actuator and found 12 volts on one of the pins and nothing changes on any of the pins when the 4x4 lever is moved.  The wire that connects to the sensor on the transfer case has about 10 volts on the center pin and another pin has continuity to ground.  I've even, just for good measure and no results, taken the ground off the cab under the drivers side door and shined up all of those surfaces and put it back on, nothing.  Also, the battery has been disconnected for several hours so the computer would've been reset.  I'm at a loss at this point.

 

Any suggestions as to the cause of such a problem?

Check fuses?