Ok I have a 2000 blazer ZR2 it will go into 4wd but only the HI side and the light flashes the whole time but is engaged !!??
But will not go into Lo!!!! I replaced the the indicator sensor on the front diff and the shift modul in the pass kick panel !!
I have read and read and the local dealer said it was the control modul and well it still don't work the only thing left is the encoder or the switch !!! Any help ???

 

Here start with this read before you replace anymore part's
https://blazerforum.com/forum/tech-a...ill-help-7180/

If I remember that module is pretty pricey, your dealer is one of two things malicious or an idiot. See if you can get someone with a good scanner to read your codes. I think $25 would be fair.

One thing I will say is the dash switch does go bad frequently and if I were to change something without proper diagnosis it would be that. They are cheap and hard to really check.

 

Thanks I will ck it out