1. Check for Power at the Fuel Pump Relay:
* Locate the Fuel Pump Relay: Consult your owner's manual or a repair manual for the location of the fuel pump relay. It's often in the under-hood fuse box or a separate relay center.
* Identify the Relay: The relay may be labeled, or you might need to use a wiring diagram to identify it definitively.
* Test for Power: Turn the ignition key to the "ON" position (don't crank the engine). Using a test light or multimeter, check for power at the relay's power input terminal. You should have battery voltage (12V). If you don't, trace the power wire back to the fuse and check that fuse.
* Check for Power at the Relay Output: With the ignition still "ON," check for power at the relay's output terminal (the terminal that leads to the fuel pump). If you have power here, the relay is working and the problem is likely with the fuel pump or its wiring. If there's *no* power here, the relay itself might be faulty. Swap the relay with a known good relay of the same amperage rating to verify.
2. Check for Power at the Fuel Pump:
* Locate the Fuel Pump: This is usually located inside the fuel tank. Accessing it requires dropping the fuel tank (a more involved task, often requiring specialized tools). *You should relieve fuel tank pressure before attempting this.* Do this by briefly turning the ignition on and off several times to allow the fuel pump to cycle, or consult your repair manual for safer methods. Never do this near open flames or sparks.
* Disconnect the Fuel Pump Connector: Carefully disconnect the electrical connector to the fuel pump.
* Test for Power: With the ignition "ON," check for power at the fuel pump connector wires using a test light or multimeter. You should have battery voltage (12V) at the connector. If you do, the problem is likely a faulty fuel pump. If you don't, there's a wiring issue between the relay and the fuel pump.
3. Test the Fuel Pump (if power is present at the pump):
* Pressure Test: The most definitive test is a fuel pressure test, which requires a fuel pressure gauge. Connect the gauge to the fuel system's test port (location varies by vehicle, consult your repair manual). Turn the ignition "ON" and observe the fuel pressure. The pressure should build to a specified value (consult your repair manual for the correct value for your engine). Low pressure or no pressure indicates a faulty pump.
* Listening Test (Less Reliable): With the ignition "ON," you can position yourself near the fuel tank and listen for the whirring sound of the fuel pump running. However, a weak pump might make a faint sound, or a noisy pump may not be faulty. This method is not a definitive test.
Important Considerations:
* Safety First: Gasoline is extremely flammable. Work in a well-ventilated area, away from any ignition sources.
* Repair Manual: A repair manual specific to your 1991 Dodge Spirit is highly recommended. It will provide detailed diagrams and specifications for your vehicle.
* Professional Help: If you are not comfortable performing these tests or repairing the fuel pump yourself, take your vehicle to a qualified mechanic.
By systematically following these steps, you can isolate whether the problem is a lack of power to the fuel pump, a faulty relay, or a faulty fuel pump itself. Remember safety is paramount when working with fuel systems.
