Generator fails to start; controller displays AL04 – Low Fuel Level Shutdown or Warning

Safety first: Turn the generator to STOP and isolate battery negative. No smoking or open flames near the fuel system.

• Verify actual fuel level: Check the mechanical gauge on the base tank or day tank. If low, refill with the correct diesel grade. Ensure the tank vent is not blocked.
• Inspect fuel level sender: Locate the level sender on the tank top. Check wiring harness and connector for corrosion or damage. Lightly tap the sender body to see if the reading changes on the controller (indicating a sticking float).
• Bleed fuel system: If the tank ran dry, air may be trapped. Use the manual priming pump on the engine or fuel filter head. Loosen the bleed screw on the fuel filter and pump until fuel flows without bubbles, then retighten.
• Check fuel filters: Inspect primary and secondary fuel filters for clogging. Replace if dirty, following engine manufacturer torque specs and priming procedure.
• Test run: Clear the alarm, set to MANUAL, and start. Monitor for stable running and that the fuel level reading on the controller is reasonable.