i have a 1998 blazer it has the 32 pin tccm it is brand new i tough it was bad so i replaced it with a new one that did not do it. here is what it dose you push the button and the tccm clicks a couple of times ans the 2wd light stays on and the what ever 4wd button i push it flashes while the 2wd light stays solid

 

Never Mind I found out my issuer word to the wise check the atc fuse