Where is the thermostat located on a 1996 Chevy Blazer?

The thermostat on a 1996 Chevy Blazer is located on the engine, underneath the intake manifold. It's not easily accessible and requires removing parts of the intake to reach it. You'll need to consult a repair manual specific to your Blazer's engine (4.3L V6 or 5.7L V8) for detailed instructions and diagrams. This is not a job for a beginner mechanic.