Problems With 4x4 Hi Not Working

[fargomiller]

I am having issues with my 1996 k1500 suburban's 4x4. It has push button 4x4 and when I hit 4 hi the light blinks several times and then goes back into 2 hi. When I push 4 lo it blinks and I hear a click and it goes into 4 lo. Then if I would hit the 4 hi the light blinks, I hear a click and it goes into 2 hi.

 

What could be wrong with my 4 hi?

 

P.S. the click is the sound of the 4x4 engaging or disengaging.