2002 blazer wont go into 4hi

My blazer will not engage into 4hi. when i push the button it doesnt do anything. Not even light up. I can put it in neutral and it will go into 4Lo but not 4hi. what do i need to do. I tried replacing the buttons but that didnt fix the problem. please help
Shawn

Your description of the suymptoms seems to indicate a control problem more than a mechanical problem with the transfer case or front axle. Testing the transfer case actuator/encoder and control module would be the fastest route to a solution.

Welcome to the forum and its not hard to fix - Use the Search function and you will find many posts and go to the How To section also. Just step thru the possible items - most of us have at some point! Always post year and model as well as type of case - 3 button is 233 and 4 button a 236 auto case then theres the Bravada 136 full time wonder.

It has a 3 button switch. Do you know if there is a seperate relay for 4hi and 4lo. im not having any luck so far fixing this

It has a 3 button switch. Do you know if there is a seperate relay for 4hi and 4lo. im not having any luck so far fixing this

You need to check the system for codes and see what shows up and post back code.
Here is a little info but it is out of of a 00 instead of 02 book may be a little different.
http://members.troublecodes.net/crunch/02t.pdf

If you are going to get very far in to the repair I would suggest a ALL data sub.
24.95$ US plastic and 10 minutes and you can have all test and repair info and tsb's and wiring diagrams and parts locater on it.
Well worth the money and can save hundred's of dollars on one repair.
http://www.alldata.com/products/diy/index.html
Also a good search on this site may show your problem.
Post back any codes you get.