I have a 1993 Ford Ranger 4x4. I have replaced the shift motor, the computer-controller, and the speed sensor. When I push the 4x4 H switch, the motor will turn about 3/4 of the way there but stops short of going into gear. When I push 4x4 L switch it stays the same place. I have hooked up the wiring with the shift motor off the transfer case where I can watch the motor position while my wife pushes the buttons. The lights light up correctly and when I push the 4x4 H switch again the motor returns to the 2 wheel position. Help! This thing is driving me nuts.