I have a 98 chevy blazer i just replaced the engine and my 4x4 is stuck in 4 lo my tansfer case control mod is ok vacuum lines actuator im wodering if its my transfer case motor gone bad i have the 3 switches on dash but i cant change settings not even by putting blazer in neutral i just stays in 4 lo any ideas as to what is going on here please help!

 

did you check the fuse panel??

 

Also, if you do not have Auto4WD, then you could go through the diagnostic trouble steps detailed in the OBD2 Non-Automatic Transfer Case Diagnostics. That should give you any codes that may be present.