Follow the top radiator hose to where it meets the engine. In that roundish housing( with two bolts) that the hose attaches to, is the thermostat. Be careful when tightening the bolts. Do not crank down on them. I don't know the official torque(how tight). Just snug them. ..........Hey, anybody know how to test the radiator cap?..........Hey Chad, remember...righty tighty, lefty loosey! Except for a Skillsaw.