Hello, my name is Robert and I have a 2003 blazer that when the truck is on jack stands, the front drive shaft is turning but the wheels are not. Any ideas on where to start with this problem?

 

I believe your front differential is not locked. Your transfer case is engaged but your front diff isn't. Apparently there is this front axel vacuum that is located underneath the battery. That is more than likely broke and is not engaging the front axel.

This video explains it better.


Hope that helps! Good luck!