Can not engage any 4 wheel drive

I have an on the floor 4 wheel drive shift lever. I can not move it forward or back, it will move side to side. Can not engage any 4 wheel drive. Is this a totally manual shifting application or is there some type of electronic switch that controls this? Tried both forward and reverse, it won't move. Is this model totally manual shift (no electronic or vacuum? I live in northern Wisconsin and maybe the linkage is frozen due to rust etc.

Today we got our first snow and discovered that the 4X4 was not engaging. The 4H and 4L light would come on but no 4x4. When switching into 4L I would hear a clunk and then when pulling forward it was geared down but only the rear tires would spin. In 4H turning a corner every once in a while I would hear one clunk but nothing would happen. 4H nothing would happen. I switched back and fourth a few times and the last time it clicked in the dash 5 or 6 times and the light went out. Not neither 4H or 4L light will come on and couldn't hear any clicking or clunking under the truck. I have checked fuses and all appear to be good. I was hoping for it to be an easy fix since this is my first year to push snow. Can anyone please help me?