diagnostics 4x4 system for a 1998 Chevy s-10 pick up

First check fuses. Next replace the transfer case switch it is located in front of the transfer case it has two wires on it. They go all the time. next check for vacuum lines. They run off your cruise control reservoir to a vacuum switch near the firewall and then to the 4wd diaphragm . This diaphragm is located under the battery. You must remove the battery tray to get to it. It sometimes rips. If I were a betting man I'd go with the transfer case switch.

did ya get er fixed?