FORD RANGER TRANSFER CASE

When I Turn The Knob 4x4 High Or Low I Hear A Low Sounding Click But It Does Not Engage, And 4-wheel Drive Does Not Work. The 4x4 Lights...

I Picked Up A Used Ranger. Guy Says The Transfer Case Actuator Needs To Be Replaced And 4x4 Will Work. I Order The Actuator And Climb Under...