The fuel system of a car is one of the most important parts of the vehicle. It’s responsible for delivering fuel to the engine and converting it into energy to power the car. The fuel pump is a crucial part of this system as it pumps fuel from the gas tank to the engine. In this article, we will discuss the fuel pump wiring diagram of the 2003 Ford Expedition.
What is a Fuel Pump Wiring Diagram?
A fuel pump wiring diagram is a schematic representation of the electrical connections and components involved in the fuel pump system. This diagram is essential when troubleshooting fuel pump issues as it helps in identifying the cause of the problem. It also serves as a guide for repairing or replacing faulty wiring or components.
The fuel pump wiring diagram of the 2003 Ford Expedition consists of several components, including the fuel pump relay, fuel pump fuse, fuel pump inertia switch, fuel pump, and wiring. We will discuss each of these components in detail.
Fuel Pump Relay
The fuel pump relay is an electrical component that controls the fuel pump’s operation. It’s located in the central junction box of the vehicle, which is located under the dashboard on the driver’s side. The fuel pump relay’s primary function is to regulate the fuel pump’s power supply by controlling the electrical current that goes through it.
The fuel pump relay of the 2003 Ford Expedition is a 4-pin relay. The first two pins are for the control circuit, and the second two are for the power circuit. The control circuit is connected to the powertrain control module (PCM), which sends a signal to the relay to turn on or off. The power circuit is connected to the battery, which provides the electrical current that powers the fuel pump.
How to Test the Fuel Pump Relay
If your fuel pump is not working, testing the fuel pump relay can help you identify the problem. Here’s how to test the fuel pump relay of the 2003 Ford Expedition:
| Step | Action |
|---|---|
| 1. | Turn off the ignition and remove the fuel pump relay from the central junction box. |
| 2. | Locate pins 30 and 87 on the relay. These pins are for the power circuit. |
| 3. | Use a voltmeter to check if there’s continuity between pins 30 and 87. If there’s no continuity, replace the relay. |
| 4. | If there’s continuity, use a jumper wire to connect pins 30 and 87. |
| 5. | Turn on the ignition and listen for the fuel pump. If the fuel pump is working, replace the fuel pump relay. If not, check the fuel pump fuse, wiring, and inertia switch. |
Fuel Pump Fuse
The fuel pump fuse is a safety device that protects the fuel pump from electrical overload. It’s located in the central junction box, along with the fuel pump relay. The fuel pump fuse of the 2003 Ford Expedition is a 20-amp fuse, and it’s labeled as F17 in the central junction box.
If the fuel pump fuse is blown, the fuel pump won’t receive any electrical current, and it won’t work. To check the fuel pump fuse, use a voltmeter to check if there’s continuity between the two terminals. If there’s no continuity, replace the fuse with a new one of the same amperage rating.
Fuel Pump Inertia Switch
The fuel pump inertia switch is another safety device that shuts off the fuel pump in case of an accident. It’s located in the passenger compartment, near the right-hand side kick panel. The fuel pump inertia switch of the 2003 Ford Expedition is a black box with a red button on top.
If the fuel pump inertia switch is tripped, the fuel pump won’t receive any electrical current, and it won’t work. To reset the fuel pump inertia switch, press the red button on top of the switch. If the switch is working correctly, you should hear a clicking sound when you press the button.
Fuel Pump Wiring
The fuel pump wiring is the electrical connections that link the fuel pump to the components that control it. The wiring includes the power and ground wires, which provide the electrical current that powers the fuel pump. The fuel pump wiring of the 2003 Ford Expedition is color-coded, and it’s essential to follow the correct wiring diagram when repairing or replacing any faulty wiring.
Frequently Asked Questions (FAQ)
Q1. What are the signs of a faulty fuel pump in a 2003 Ford Expedition?
A1. Signs of a faulty fuel pump in a 2003 Ford Expedition include difficulty starting the engine, engine stalling or hesitating, and reduced fuel efficiency.
Q2. Can I drive my 2003 Ford Expedition with a faulty fuel pump?
A2. It’s not recommended to drive your 2003 Ford Expedition with a faulty fuel pump, as it can lead to engine damage and safety hazards.
Q3. How much does it cost to replace a fuel pump in a 2003 Ford Expedition?
A3. The cost of replacing a fuel pump in a 2003 Ford Expedition depends on the fuel pump’s brand, type, and labor cost. On average, it ranges from $500 to $800.
In conclusion, the fuel pump wiring diagram of the 2003 Ford Expedition is a crucial tool in troubleshooting fuel pump issues. It’s essential to follow the correct wiring diagram when repairing or replacing any faulty wiring or components. We hope that this article has been helpful in understanding the fuel pump system of the 2003 Ford Expedition.
