I get codes from the 4 wheel drive and the selector buttons will not light up, and nothing will enguage when I push the buttons.
Is there something I should be looking for inparticular?
I really need help with this

 

Hanr3 wrote a great little synopsis of the 4WD system on the Blazer. Read through it and you will probably be able to figure out your problem.
https://blazerforum.com/m_52228/tm.htm
Don't really want to go much further because you didn't state any specs about your blazer so I don't want to post any misinformation. See if you have fuses that are labled ATC or ATF and check them. What codes are you getting ?

 

Thanks for the Kudos.