Current Problems
If current isn’t flowing through the fuel pump, the fuel pump, fuel pump ground circuit, fuel pump relay or, if equipped, the fuel pump safety inertia switch might be defective. If current is flowing through the fuel pump, then it’s highly likely that the external fuel filter might be clogged or that the filter sock attached to the fuel pump inlet might be clogged with dirt, algae or rust contamination.

If current is flowing through the pump and the normal fuel pump operating noises aren’t present, the inlet sock is probably missing and the mechanical part of the fuel pump is likely jammed with sand or other types of fuel tank contamination.
 
Voltage Issues
If voltage is available at the fuel pump, it’s important to inspect the tank’s electrical connector for looseness and burned connector pins. Repeat failures are often caused by connectors that were burned due to excessive amperage draw of a defective pump.

If the fuel pump circuit is grounded to the frame, perform preventive maintenance by cleaning the frame and connector, and applying anti-corrosion compound to the connection. See Fuel Photo 1.

Don’t Get Baffled
If the fuel pump’s inlet filter is missing, torn or broken, make sure that the fuel tank baffle is securely attached to the fuel tank. I’ve had at least one instance of multiple fuel pump failures caused by a loose tank baffle battering the fuel pump until the inlet filter fell way, thus allowing sand to jam the pump assembly. See Fuel Photo 2.