i have a 1998 chevy blazer 4 dr 4x4 i have a 3 button switch on dash i put truck in nutreal and hit 4hi nothing but i hit 4lo and it makes a click nois and gos into 4lo but when i go from 4lo to 4hi it clickes and u can hear it try n shift but gos back to 2wd any one kno a fix i just got back from army and ex wife took all money i litteraly have 20 buckes to my name any help pls

 

There are many others that have experienced the same thing as you detailed in more than a few threads on the subject.

Start out by having a look at the 96+ NV233 diagnosis link in my signature.

 

the problem is related to the vaccuum line for the 4 hi. there is the 4x4 vaccuum actuator on the firewall that has 2 lines on it. i found my issue which was same as yours the vaccuum line that leads to the drivers side is for the 4 low the line that leads to the right is for the 4 hi. either its disconnected or has crack and leaking. could possibly be actuator one way to check is to swap the bottom line to the top and vice versa and see if the 4 lo doesnt go in and 4 hi does