4x4 Inop

I have 96 Sierra 4x4. The front axle will not engage. I replace the switch on transfrer case with no results. There is NO power coming out of the switch when in 4 wheel drive. What operates the switch in the transfer case? Been trying to fix since middle of January. Really need 4 wheel drive for up coming fishing season!!!!

is the 4x4 fuse good, power to the brown wire at the transfer case switch?

Change the thermal acuator on the front end. Had the same problem this winter.

Checked the fuse, right?