94 Ford Explorer 4x4

94 Ford Exp 69K. 4x4 is not working. Some times the lights next to the
selector buttons on the dash will both light dimily. Nothing is heard
when pressing either. Some times the lights go out. The other day
pulling into the drive way they both lit and the 4X4 indicator on the
dash came on. The car was not in 4X4 because I drove it on the road
and made some tight turns and it would have been obvious if it was in
fact in 4 wheel. This light stayed on for approx 2 hours then went out
and both push button switches went back to dimly lit. I have read
posts about looking the the 4X4 module in the rear driver side panel
and watching led's or pressing the reset button. On mine there are no
led's or a reset button only a black box. Has anyone had these issues?
Any Ideas?