Where is the thermostat on a 99 Ford Taurus 3.0 dohc 24 valve?

On a 1999 Ford Taurus with a 3.0 DOHC 24-valve engine, the thermostat is located at the engine's front, near the water pump. You'll need to remove the upper radiator hose and the thermostat housing to access it. It's typically secured with bolts, so you'll need the appropriate tools to remove the housing to replace or inspect the thermostat.