My 03 zr2 blazer is STUCK in 4x4. I try to switch it on the dash but the light blinks and then stays in 4x4. You can hear it clicking and trying to switch but nothing happens. We've checked the vacuum actuator and the front driveshaft turns...but other than that were really just at a lost..ANYTHING is helpful!!!!!!!!!!!

 

Sorry little late hope you fixed it already but mine did the same thing try doing about 30 on a straight road hit the 2wd button and slam on the brakes, helped mine it might make a really loud slamming noise but itll engage it to 2wd also try putting nee vaccum lines from actuator to front diff might have pin hole in it