Chevrolet Repair: 4X4 SHIFT PROBLEMS, push button switch, s10 blazer

Question
94 S10 BLAZER VORTEC V6 WITH 4WD PUSH BUTTON SWITCH.WILL NOT SHIFT INTO 4WD.I REPLACED THE VACUUM SWITCH ON THE TRANFER CASE LAST YEAR AND GOT IT WORKING. IT STOPPED WORKING AGAIN SOMETIME AFTER THAT,AND I CHECKED VACUUM SWITCH AND IT LOOKED OK.I ALSO CHECKED THE VACUUM CANISTER UNDER THE BATTERY, IT APPEARED OK.THEN I PULLED THE ELECTRIC PLUG OFF THE TRANSFER CASE AND I CLEAN THE TERMINALS PUT IT BACK TOGETHER AND IT  WORKED FOR A SHORT TIME (2 MONTHS MAYBE).FUSE WAS ALSO CHECKED.BUT NOW I TRIED ALL THE SAME THINGS AND CAN NOT GET IT WORKING. I REALLY DON'T KNOW THE PROCEDURE FOR CHECKING ALL THE COMPONENTS OF THIS SYSTEM.ANY ADVISE WOULD BE GREATLY APPRECIATED.        THANK YOU,TOM  

Answer
Hi Tom,
I will send a couple links, one with a troubleshooting proceedure.
The links are from a company trying to sell mechanical actuators, which may be a good idea. I don't have any though. I use stock actuators. It is interesting reading though.
You will need to find out if the transfer case is actually shifting, and just the front axle is not engaging.
Your problem could be the electric transfer case shifter not working.

Here are those links.

http://www.4x4posi-lok.com/PDFs/troubleshootguide.pdf

http://offroadltd.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=ORL&Product_...

And then go to this link and search through the forums. You will probably want to sign up....it is totally free, and endless information.

http://www.chevytalk.org/

Van