What is the location for the coolant temp sender for the temp gage. on 2006 Chevrolet Colorado

Gage is reading 3/4 but the engine is not running hot. Have replaced radiator, water pump, belt, and thermostat, flushed system and new coolant. Gage has always read half or below even on hot days.

Asked by for the 2006 Chevrolet Colorado
You maybe has air in your system let the air out before buying parts.