Looks like everyone missed you- sorry.
99up have an additional vac switch on the firewall that the dash switch activates so pull the vac line there to see if the front actuator releases then hook it back up and disconnect the electrical plug connector and see it that solves it (bad vac switch) or it could be the dash selector switch, the TCCM or computer for 4wd behind the pass kick panel. Are you getting a solid light and not flashing on the dash switch?