1. Check the Fuses: Start with the easiest and most common cause. Your Bronco's owner's manual will show you the fuse box location and diagram. Look for fuses related to the fuel pump or fuel injection system. Visually inspect them for blown elements (a broken filament).
2. Relay: The fuel pump is usually controlled by a relay. This is an electrically controlled switch that handles the high current draw of the fuel pump.
* Locate the Relay: Find the fuel pump relay in your under-hood fuse box or in a separate relay center (location varies depending on your Bronco's specific configuration; consult your owner's manual or a wiring diagram).
* Test the Relay: You can test the relay by swapping it with a known good relay of the same amperage rating (from another circuit if possible). If the problem is solved by swapping, you need a new relay. You can also use a multimeter to test the relay's internal continuity, but this requires more electrical knowledge.
3. Inertia Switch: Some vehicles have an inertia switch that cuts power to the fuel pump in a collision to prevent a fire. This switch is usually found under the dash or in the engine bay. Check if the switch has tripped (often a button that needs to be pushed in to reset).
4. Wiring: Problems in the wiring harness between the fuel pump relay and the fuel pump are common causes.
* Visual Inspection: Check the wires for any signs of damage (breaks, fraying, corrosion). Pay close attention to the wires near the fuel tank, which are prone to chafing and wear.
* Continuity Test: Use a multimeter to test for continuity in the wiring between the fuel pump relay and the fuel pump. You'll need a wiring diagram to identify the correct wires. A lack of continuity indicates a broken wire.
5. Fuel Pump Circuit: The power supply to the fuel pump relay itself could be an issue. Check the power and ground connections to the relay. This often involves checking fuses again, but also the larger wiring harness connections.
6. Fuel Pump Driver Module (PDM): Some models use a Power Distribution Module (PDM) which controls multiple electrical components, including the fuel pump. A faulty PDM can prevent power from reaching the fuel pump. This is a more complex issue requiring specialized testing or replacement.
7. The Fuel Pump Itself: While less likely if there's *no* power reaching it, a completely failed fuel pump is possible. This would require removing the fuel pump to test it (a messy job).
Important Safety Precautions:
* Disconnect the battery's negative terminal before doing any electrical work.
* Work in a well-ventilated area when dealing with fuel-related components.
* Never work around fuel with any open flames or sparks.
* If you are not comfortable working with car electrical systems, take your Bronco to a qualified mechanic.
By systematically checking these points, you should be able to pinpoint the cause of the power problem to your fuel pump. Remember to consult a wiring diagram for your specific Bronco model – this is invaluable for tracing circuits and identifying wire colors.
