* Ignition Switch: This is a common failure point in older vehicles. The ignition switch might be failing to send the correct signal to the starter motor. This is a strong possibility given your symptoms.
* Starter Motor: The starter motor itself could be faulty. Even though you hear the fuel pump, the starter isn't engaging to crank the engine. This could be a bad solenoid within the starter, or the motor itself is seized or worn out.
* Neutral Safety Switch (NSS) or Park/Neutral Position Switch (PNPS): This switch prevents the car from starting unless it's in Park (automatic) or Neutral (manual). If this switch is faulty, it won't allow the starter to engage, even if the key is turned. Check to make sure the transmission is definitely in Park or Neutral.
* Starter Relay: This relay acts as an intermediary between the ignition switch and the starter motor. A failed relay will prevent power from reaching the starter.
* Wiring Issues: A corroded, broken, or loose wire in the starting circuit could interrupt the electrical flow. This requires a more thorough inspection of the wiring harness.
* Security System (if equipped): If your Astro has a factory or aftermarket security system, it might be preventing the vehicle from starting. Check for any security system indicator lights and consult your owner's manual.
Troubleshooting Steps:
1. Check the Transmission: Double and triple check that the vehicle is in Park (automatic) or Neutral (manual). This is the easiest thing to check and often overlooked.
2. Have the battery and charging system tested: Even with a new battery, a faulty alternator could be draining the battery faster than it charges. This should be checked with a load tester at an auto parts store.
3. Check Starter Relay (if accessible): Locate the starter relay (consult your owner's manual or online resources for your specific Astro model). Try tapping it lightly with a screwdriver handle (sometimes helps if it's sticking) or swap it with a known good relay of the same type (if you have one).
4. Listen Carefully at the Starter: When you turn the key, have someone listen closely to the starter motor itself. You might hear a click or a faint whirring sound, which can help pinpoint the issue.
5. Test the Ignition Switch: This is difficult to do without specialized tools, but a mechanic can easily test this component.
6. Visual Inspection: Check for any obvious signs of corrosion or damage to the wiring around the battery, starter, and ignition switch.
Recommendation: Unless you have experience working on automotive electrical systems, it's best to take your Astro to a qualified mechanic. They have the tools and expertise to diagnose and repair the problem efficiently and safely. The problem is likely in the starting circuit, and incorrectly diagnosing could lead to further damage.
