My Lumina not getting power to the fuel pump?

If your 1992 Chevy Lumina is not getting power to the fuel pump despite the fuse and relay being fine, there could be several possible reasons for this issue. Here are some troubleshooting steps you can take to identify and potentially resolve the problem:

Check Fuel Pump Wiring and Connector: Inspect the wiring harness and connector leading to the fuel pump. Look for any signs of damage, corrosion, or loose connections. A damaged or disconnected wire can prevent power from reaching the fuel pump.

Test the Fuel Pump Relay: Although you mentioned that the relay is fine, it's still worth testing it to be sure. Swap the fuel pump relay with a similar relay from another circuit (e.G, A/C or horn) and see if the fuel pump receives power when you turn the key. If the fuel pump works with the swapped relay, the original relay may be faulty, even though it appears fine.

Check for Voltage at the Fuel Pump Relay: Use a multimeter to test for voltage at the fuel pump relay's wiring harness. Turn the key to the "ON" position (not crank), and check if there is voltage present at the relay terminals. If there's no voltage, there might be a wiring issue between the ignition switch and the relay.

Inspect the Ignition Switch: The ignition switch could be faulty, not sending the proper signal to activate the fuel pump relay. Test the ignition switch for continuity and proper operation.

Verify the Inertia Switch: Some vehicles are equipped with an inertia switch that cuts power to the fuel pump in the event of a collision or impact. Check the owner's manual or service manual to locate the inertia switch and verify if it has been triggered. If it has, reset the switch to restore power to the fuel pump.

Check the Engine Control Module (ECM): The ECM controls the operation of the fuel pump relay. If the ECM is not functioning correctly or has a wiring issue, it may not send the signal to activate the fuel pump relay.

Inspect the Security System: If your vehicle has a security system or an immobilizer, it may be preventing the fuel pump from receiving power. Check for any security system warning lights or indications that suggest an issue with the security system.