I have a 2000 blazer with the 4 button 4WD switch. I realized today while trying to use the 4WD that when I went to put it into 4HI that the light just kept on flashing and didn't seem as if it was in 4WD or not, so I put it in neutral hit the 4LO button, put it back in drive and it also flashed, the only thing is, even though the 4LO button was flashing, you could definately tell that the vehilce was in 4LO. I was wondering if anybody knew what the issue could be. This is my 4th blazer/jimmy and i've never ran into this problem before.

If anybody has any suggestions for me it would be highly appreciated.

 

This is the same problem I am having. You can feel it go into 2 lo for example, but the light keeps flashing to indicate it is not in 4 wheel drive. Any Help?

 

After reading through many of the posts concerning this, I checked the vacuum hose coming from the firewall. It had been routed behind the distributor, where it had rubbed through for about an inch where it had been in contact. A nice little hose splice did the trick for me! All done in five minutes. Bobstar

 

Alright thanks, i'll take a look at it tomorrow.