Where is the thermostat at on your 2003 Chevy truck?
A 2003 Chevy truck's thermostat location varies slightly depending on the engine. It's generally found on the engine block, near the water pump, but not always in the same exact spot. To find it accurately, you'll need to consult a repair manual specific to your truck's engine (e.g., 4.3L, 4.8L, 5.3L, 6.0L, etc.). A diagram in the manual will show the thermostat's exact location.