There are a couple of fuses on the 1995 and up 4x4 system, I believe there is a 20amp fuse in the engine fuse box that can blow, this powers the module but not the dash lights, so dash lights flash to indicate a problem.
Just FYI the flashing 4x4 lights are not specific to any specific problem.
Yes, shift motor is a common problem on the rangers, it is usually from disuse, if the shift motor is not used much the contacts inside get corroded, and when you try to shift the motor doesn't move.
So once you get it working, shift to Hi and Lo once a month.
Shift motor rebuild here:
Servicing A Transfer Case Shift Motor