Verified answer

you should have a coolant sensor and a temperature sending unit ! the coolant sensor should be close to the thermostat housing !

You may have two coolant temperature sensors but the one most people refer to is the one hooked up to the coolant temperature gauge in the dashboard. This sensor is always in one of the cylinder heads close to the spark plugs and exhaust manifold. This sensor is sending the coolant temp inside the cylinder heads.

The other sensor is on the intake manifold and is what the computer uses to measure coolant temperature to adjust fuel-air mix usually after the thermostat has opened and coolant is circulating through the radiator. This one does not affect the temperature gauge on the dashboard.

Good Luck!

2008 F150

Hi so if you have to ask then best to take it to a ford garage for them to do it.