Where is the temperature sending unit on a 7.3 powerstroke diesel?

The temperature sending unit (also called a coolant temperature sensor) on a 7.3 Powerstroke diesel is located on the driver's side of the engine block, near the thermostat housing. It's usually a single-wire sensor, and can be a bit difficult to access depending on the year and modifications to the truck. You might need to remove some components for easier access.