I don't remember there being a 2002 318. Atleast not in the U.S. market.
On the upper hose at the engine end
Find the upper radiator hose and follow it to the engine. Normally it will be located somewhere where this hose meets the engine in a housing.
every where
Engine thermostat is where your upper radiator hose hooks to the top of the engine
You have a top radiator hose and a bottom radiator hose.
The thermostat in the 2002 Blazer will most likely be in the top radiator hose engine inlet, depending on the engine in the vehicle. The top hose is removed then the inlet unbolted to reach the thermostat.
The garden hose connection to the engine on a 2002 Yamaha 800 XLT is located on the side of the vehicle near the bottom of the engine. It is used to flush the coolant and restore coolant efficiency.
the hose that is connect to your engine.
under the housing where the lower hose hooks to the engine.
It is under the housing where the lower radiator hose hooks to the engine.
on the top, driver side of the engine. find the hose coming off the radiator and follow it to the engine. it is right where the hose connects.
follow the top radiator hose to the engine, the thermostat is located in the housing that that end of the hose is connected to