Because your gauge stopped working suddenly, the problem isn't necessarily the sensor itself. It could be:
* The sensor itself: A failed sensor is a possibility.
* Wiring: A broken or corroded wire between the sensor and the gauge is more likely. Check for frayed wires near the sensor and at the connector.
* Gauge Cluster: The gauge in the dashboard could be faulty.
* Grounding Issue: A poor ground connection can disrupt the signal.
Before you start hunting for the sensor, I strongly recommend:
1. Checking the wiring first: This is the easiest and cheapest thing to do. Trace the wiring from the gauge back to the sensor connector. Look for breaks, corrosion, loose connections, or damaged insulation.
2. Testing the sensor: This usually requires a multimeter and some knowledge of how to use it. Many auto parts stores can test sensors for you.
3. Checking the gauge cluster: If the wiring and sensor check out, the problem could be within the instrument panel itself. This is a more complex repair.
Do not attempt to locate or replace the sensor if you are not comfortable working on vehicles. This is a somewhat involved task that requires mechanical aptitude and the right tools. It is best to consult a repair manual specific to your 1998 Chevy Astro van (Chilton or Haynes manuals are good options) or take it to a qualified mechanic. Improperly working on your vehicle could cause further damage.
