does the 4x4 indicator light come on. if it does not i would suspect the actuator not completely engauging completly (grinding)if its any thing like my 94 the actuator pushes a sliding gear into another to engauge 4x4. the floor shifter on mine engauges the transfer case and at the same time the actuator is activated electronically to activate the front diff. you can always take the actuator out and take a socket extention and try to activate it manually have a friend inside to watch for the indicator to light. keep in mind you may have to slightly move the truck to allow the gears engauge. so take careful precautions while under there! Hope this helps you