To be certain, you should:
1. Consult a repair manual: A Haynes or Chilton repair manual specific to your 2002 Chevy Astro 4.3L will have diagrams and precise instructions showing the ECT sensor's location. This is the most reliable method.
2. Use an online parts diagram: Many online auto parts stores (like AutoZone, Advance Auto Parts, etc.) allow you to select your vehicle's year, make, model, and engine, and then view a parts diagram. Find the engine coolant temperature sensor on the diagram. This can provide a visual reference.
3. Look near the thermostat housing: This is the most common location. The sensor is usually a single-wire or two-wire sensor, and it's relatively small. Be careful when searching as there may be other sensors in the vicinity.
Important Considerations:
* Safety First: Always disconnect the negative battery terminal before working on any electrical components in your engine bay.
* Heat: The engine and surrounding components get very hot, especially after running. Allow the engine to cool completely before attempting to locate the sensor.
If you can't locate it after using these methods, consider seeking assistance from a qualified mechanic.
