2000 chevy s10 4x4 problems

i have a 2000 chevy s10 and am having 4x4 probles. the 4x4 switch on the dash wont light up. the only part that lights up is the 4hi 4lw and the 2hi but the orange indocator light doessnt come on. i replaced the switch and still nothing i change the fuse for it and it worked only for a day then stoped working. Anyone have any ideas what it could be

Need to take it into a repair shop that has access to an enhanced scan tool that can interface the transfer case control module (TCCM). There are probably trouble codes being set. Autozone or any global code checker won't be able to interface the TCCM.

Basically it is the brains of the 4wd system. It performs operations and diagnostics of the transfer case.

If the brain is storing a trouble code, that might give them a clue where to start diagnosing your problem. They can also use the scan tool and talk to the brain to tell it to do certain functions or ask the brain for information from various sensors and switches to see if they are functioning properly. Either way the brain may have some answers as to what may be going on.

When there is a brain box involved in the operation of something, it's hard to diagnose problems like that because you need to see what is going on inside the box. Your only getting half the picture of what is going on. That is were a lot of folks that come on here for problems of their own get stuck at.

Let us know how things turn out.

Water intrusion can cause problems in connectors and electrical components for sure. You also have to be careful swapping TCCMs around because the TCCM you pulled may be used to control a different model transfer case.

You should still have the TCCM scanned to see (1) that is is able to communicate and (2) if it is storing any codes.

If the connector is all green inside, you are probably going to have to repair or replace the connector. The corrosion causes resistance which can affect those circuits. Since that is pretty obvious, you should start there first. Even though the module PN may be the same the programming may be different. Once you resolve your corrosion problem, see how things work.