Where is the front differential vacuum actuator located on my 2000 Chevy blazer?

The front differential vacuum actuator on a 2000 Chevy Blazer is located on the passenger side of the front differential. It's usually a small, cylindrical device connected to both a vacuum line and a linkage arm that controls the differential's engagement. You'll likely find it near the top or side of the differential, possibly somewhat hidden behind other components. You might need a flashlight and potentially to get under the vehicle for a clear view.