hi,
im having a simalar problem with the 4wd on my 2001 blazer s10 the other day it was in auto 4wd and i tried to switch it to 2whi its buttons on the fly i pushed 2 w hi and the 4 w low started blinking then clicked in i continued to push the 2 w hi but there was nothing i even tried to push 4 w hi and nothing so i ended up driving it to a local mechanic so the could get it out of 4 w low he didnt pin point the problem its still there but at least i can drive it now if anybody has a clue as to what it is please let me know it sounds like it happens often thanks [:@]

 

Hi, I'm just new to this but it sounds like you're having the same problem my son was having with his. It ended up being the shift motor control module for the 4x4 that is piggy backed on the ECM which is located under the dash on the passenger side. You can go to auto zone's web site in their repair section and get a picture of it. I'm not sure what a new one costs but we went to a salvage yard and got one for $20. It has been working fine since. Good luck.

 

^^^^^

My '99 Blazer had blinking lights and would not stay in 2WD. They called my problem the Transfer Case Control Module (TCCM), probably the same as lilred mentioned, just different years or names. The push button shifting worked intermittantly. Seems the part was over $300, but I really don't remember.

It was rather expensive at the shop.

Bocomo