It just started today,but when i switch from 2 wheel drive to 4hi or 4low i have a hard time getting back into 2 wheel drive.The light blinks and takes a few tries to get it back into 2 wheel drive. Any suggestion ?

 

have you checked all the connections? make sure they are clean, especially at the transfer case, since that is exposed to the elements more so than the others.
also, check the DIY section of the board, to pull the codes from the tccm, see what it is telling you if there are any DTC stored.

 

how many connections are there and where are they located ?

 

I would honestly start at the one on the transfer case to clean it, but before you do that, check out this thread to read the DTC's and see if the tccm has stored any trouble codes, which could point to your problem.
https://blazerforum.com/forum/tech-a...ill-help-7180/