Well,
the procedure that I follow is the following
1- I got the electrical diagrams of the Transfer Ford Explorer 1992
2- Verify that none of the components is missing (components of function of the transfer box)
3- The truck has in the rear wing LED is running
--- In the event that this LED is paid, the controller resets (it has a white button on the side) when you review it will turn on the LED
--- you turn on the engine you put in neutral and 0 k/h oppress the 4x4 button if your LED goes out then you have a high current and your controller is protected.
In my case, what I did was hit with a small hammer to the engine that is in the Tranfer box and with that it had (in my case it was recommended to replace it was motor) but even it is working with a spot that fails again I will change it.
Well, I add the diagrams if you have a problem or it is something else you tell me
--- In the diagrams come the real colors of the
curiosity wiring where you are?
I hope this information serves you.