* Dead or Failing Battery: The most straightforward reason. A completely dead battery won't power the fuel pump (which needs electricity to run) or the lights. A failing battery might provide enough power for some things intermittently, but not consistently for the fuel pump and lights. Test the battery voltage.
* Alternator Failure: If the alternator isn't charging the battery, the battery will drain and eventually fail to power accessories like the fuel pump and lights. Check the alternator's output voltage with a multimeter.
* Blown Fuse or Circuit Breaker: The fuel pump and lighting circuits might share a fuse or circuit breaker. A blown component would interrupt power to both. Check the fuse box(es) for blown fuses, paying attention to those related to the fuel pump (often labelled "Fuel Pump" or similarly) and lighting circuits.
* Faulty Ignition Switch: This switch controls the power flow to various systems, including the fuel pump. A malfunctioning ignition switch could prevent power from reaching the fuel pump while still allowing power to some lights (or not).
* Wiring Problems: Damaged, corroded, or loose wiring in the main power distribution system or specifically in the circuits for the fuel pump and lights could interrupt power flow. This is a more difficult problem to diagnose, potentially requiring a visual inspection of the wiring harness. Look for any obvious damage, especially near the battery, alternator, and fuse boxes.
* Main Power Relay Failure: The system might use a relay to control power to the fuel pump, and a faulty relay could prevent the pump from operating.
Troubleshooting Steps:
1. Check the Battery Voltage: Use a multimeter to test the battery's voltage. It should be around 12.6V when fully charged.
2. Check the Alternator Output: Start the engine and test the alternator's output voltage. It should be around 13.5-14.5V.
3. Inspect Fuses and Circuit Breakers: Carefully check all fuses and circuit breakers related to the fuel pump and lights. Replace any blown fuses.
4. Test the Fuel Pump Relay (if applicable): Locate the fuel pump relay (usually in the underhood fuse box) and check if it is clicking when the ignition is turned on. You might even try swapping it with a known good relay of the same type.
5. Visual Inspection of Wiring: Look for any obvious damage, corrosion, or loose connections in the wiring harness, especially around the battery and fuse boxes.
If you're not comfortable performing these checks, it's best to take the Astro to a qualified mechanic for diagnosis and repair. Working with automotive electrical systems can be dangerous if you're unfamiliar with proper procedures.
