Sounds like you have either a bad encoder motor on the transfer case, or the transfer case control module has a problem. I have had a few of them that suddenly acted normal again after cutting off the power from the battery by disconnecting it.
The encoder motor isn't that difficult to change, neither is the TCCM. I have also seen this problem caused by a defective dash switch. But that is usually on the 01-02 trailblazers.
As far as being the worst GM vehicle, it can't be very bad considering they were built from 1982-2005 with very little actual mechanical changes.
Thursday, December 11th, 2008 AT 9:38 PM