4 Wheel Drive/SUVs: electronic 4x4 not working, push button switch, ford bronco

Question
I have a full size 1989 ford bronco with the electronic locking 4x4. I have a repair manual but it doesnt seem to be much help. When i push the button nothing happens. the 4x4 light will not even come on. it will not even try to shift into 4 wheel. everything else is working fine, except that. I took the 4x4 switch out of the dash and tested for power and the only power i get is from the illumination wire when i turn my headlight switch on. Is there a seperate fuse that runs the 4 wheel, or could this be a elctronic control problem, i have worked on it for 3 days now and just cant find the power source for the push button switch, if you could give me an idea of what it could be it will be greatly appreciated, thanks.

Answer
Jerry,

I would start at the transfer case, and start checking the wiring, and making sure that the transfer case has a good ground.  From there, I would start tracing wires to see if you may have a broken one, or bad connection.  Your manual should give you some color codes and test points in the wiring diagram.  If you are having problems with this manual, you might see if you can find better information in another manual such as Haynes, or Chiltons.

Carl