Push button doesn't engage 4WD on 1993 Subaru Loyale

For some reason when I push the 4WD button on shifter, it doesn't engage the 4WD. Any suggestions as to what he culprit could be?

Asked by for the 1993 Subaru Loyale
Hi, I'm having a similar problem with my Subaru, what did you do to fix yours?
Actuator motor on transmission that engages 4wd is not operating.