1. Check the Fuse:
* Locate the fuse: Consult your owner's manual to find the fuse for the fuel pump. It's likely a high-amperage fuse.
* Inspect the fuse: Remove the fuse and visually inspect it for a blown element (a broken wire inside). Replace it with a fuse of the *same rating* if it's blown. Don't use a higher-rated fuse.
2. Check the Relay:
* Locate the relay: Your owner's manual should show the location of the fuel pump relay. It's often in the under-hood fuse box or an interior fuse box.
* Inspect the relay: Visually inspect the relay for any obvious damage. You might be able to swap it with a similar-looking relay (carefully noting its location and function before doing so) to see if that resolves the issue. If you have a spare relay known to work, that's the best way to test this.
* Check the relay contacts: If you're comfortable, you can carefully remove the relay and inspect its contacts for corrosion or damage.
3. Check the Wiring:
* Visual Inspection: Trace the wiring from the fuel pump to the relay and fuse. Look for any broken, frayed, or corroded wires. Pay close attention to areas where the wiring harness might rub against other components.
* Continuity Test (Advanced): If you have a multimeter, you can test the continuity of the wiring. This requires disconnecting the wires at various points and checking for a complete electrical circuit. Caution: Only attempt this if you are familiar with electrical testing and understand the safety precautions involved. Incorrect testing could damage your vehicle's electrical system.
4. Fuel Pump Inertia Switch:
* Locate the switch: Some Ford Mondeos have an inertia switch that cuts power to the fuel pump in the event of a collision. Locate this switch (usually under the dash or in the engine bay) and check if it's tripped. There's usually a button to reset it.
5. Fuel Pump Control Module (PCM):
* Advanced Issue: A faulty PCM (Powertrain Control Module) can prevent the fuel pump from receiving power. Diagnosing this requires advanced diagnostic tools, typically a scan tool that can read fault codes from the vehicle's computer.
6. Low Fuel Level:
* Simple Check: While it seems obvious, ensure you have enough fuel in the tank. Some systems will cut power to the pump if the level gets extremely low to prevent damage.
Important Considerations:
* Safety First: Always disconnect the negative battery terminal before working on any electrical components.
* Professional Help: If you're not comfortable performing these checks, it's best to take your vehicle to a qualified mechanic. Incorrectly diagnosing or repairing electrical issues can lead to further damage.
By systematically checking these points, you should be able to pinpoint the source of the problem. Remember to consult your owner's manual for specific locations of fuses, relays, and other components. Good luck!
