Understanding your 2003 Ford Expedition’s fuse box is crucial for diagnosing and resolving electrical issues. This guide provides a detailed fuse box diagram specifically for the 2003 Ford Expedition model, helping you pinpoint problems efficiently. While this article focuses on the fuse box, it’s important to remember that modern vehicles like the 2003 Expedition also utilize an OBD2 system for comprehensive diagnostics. Knowing both your fuse box layout and OBD2 system can significantly aid in car maintenance and repair.
The fuse panel in the Ford Expedition (2003-2006 models) is located inside the passenger compartment. Specifically, you’ll find it under the right-hand side of the instrument panel. This power distribution box is easily accessible for inspection and fuse replacement.
Below is a detailed fuse diagram for the power distribution box in the passenger compartment of the 2003 Ford Expedition. This table outlines each fuse number, its amperage, and the circuits it protects. Understanding this layout is the first step in diagnosing electrical problems.
| № | A | Description |
|---|---|---|
| 1 | 7.5 | Run/Accessory – Front wiper motor, Instrument cluster, Rear wiper motor |
| 2 | 20 | Turn signal/Hazard flasher, Stoplamp switch, Stoplamps, Center high-mount stop light (CHMSL), Turn signal lamps |
| 3 | 7.5 | Power mirror switch, Power mirrors (non-memory), Driver seat switch (memory), Memory module (logic power) |
| 4 | 15 | DVD player, Rear seat audio controls, CDDJ (navigation radio) |
| 5 | 7.5 | Powertrain Control Module (PCM) (KA power), Speed control deactivation switch, Manual climate control mode switch, Stoplamp switch, Brake-shift interlock (BSI) solenoid, EATC control head, Body Security Module (BSM) (KA power), 3rd row seat relay coils, SecuriLock LED |
| 6 | 15 | Headlamp switch (parklamps and switch backlight feed), Parklamps, License plate lamps, Foglamp relay coil, Trailer tow electric brake controller (illumination), BSM (autolamp, parklamps) Foglamp indicator |
| 7 | 5 | Radio (start signal) |
| 8 | 10 | Rear window defroster switch, Rear window defroster indicator (climate control head), Heated outside mirrors |
| 9 | – | Not used |
| 10 | 20 | Trailer tow back-up lamps relay, Trailer tow 7–wire connector (back-up lamps), Trailer tow parklamp relay, Trailer tow 7– and 4–pin connectors (parklamps) |
| 11 | 10 | A/C compressor clutch relay, A/C compressor clutch solenoid, 4×4 Integrated Wheel Ends (IWE) solenoid |
| 12 | 15 | Fuel pump relay, Fuel pump shut-off switch, Fuel pump driver module, Fuel pump motor |
| 13 | 10 | Manual climate control mode switch, Rear window defroster relay coil, A/C refrigerant containment switch, A/C de-icing switch, A/C low pressure switch, DATC control head, DATC solenoids, DATC blower control, Trailer tow battery charge relay coil |
| 14 | 10 | Daytime Running Lamps (DRL) ignition relay coil, Digital Transmission Range Sensor (DTRS) back-up lamps, Trailer tow back-up lamps relay coil, Electrochromatic mirror, Manual A/C blend door actuator |
| 15 | 5 | AdvanceTrac® with RSC switch, Instrument cluster (Run/Start feed) |
| 16 | 10 | BS/AdvanceTrac® with RSC module (Run/Start feed) |
| 17 | 15 | Foglamps |
| 18 | 10 | Auxiliary A/C temperature blend door actuator, Auxiliary A/C front auxiliary control, Turn signal flasher, Electrochromatic mirror, Auxiliary mode motor |
| 19 | 10 | Restraints Control Module (RCM) |
| 20 | 30 | BSM (door locks, liftgate glass release relay), Liftgate glass release motor, Door/Liftgate lock motors |
| 21 | 15 | Instrument cluster (B+), Interior (courtesy) lamps, Puddle lamps (outside mirrors) |
| 22 | 10 | Moonroof switch illumination, Radio (delayed accessory feed), Flip window switch, Flip window motors, EHAM antenna amplifier (navigation radio) |
| 23 | 10 | RH low beam |
| 24 | 15 | Interior demand lamps (front map/dome lamp, 2nd row dome/map lamp, glove compartment lamp, cargo lamp, roof rail lamps, vanity mirror lamps), Battery saver relay coil, Battery saver relay power, Heated Positive Crankcase Ventilation (PCV) valve |
| 25 | 10 | LH low beam |
| 26 | 20 | Horn relay, Horns |
| 27 | 5 | Compass module, Reverse sensing system module, Brake shift interlock solenoid, Overdrive cancel switch, Air suspension module (Run/Start sense) |
| 28 | 5 | PCM relay coil, SecuriLock transceiver, Heated PCV valve relay coil |
| 29 | 30 | Trailer tow electric brake controller, Trailer tow 7–wire connector (electric brake) |
| 30 | 25 | Air suspension module (air spring solenoids and height sensors), PCM (4×4 transfer case clutch) |
| 31 | 20 | Radio (B+), Subwoofer |
| 32 | 15 | Catalyst Monitor Sensors (CMS), Transmission solenoids, Canister vent solenoid, HEGO sensors, VMV solenoid, A/C compressor clutch relay coil, CMCV, VCT actuators |
| 33 | – | Not used |
| 34 | 15 | PCM, Fuel injectors, Mass Air Flow (MAF) sensor |
| 35 | 20 | Instrument cluster high beam indicator, High beam headlamps |
| 36 | 10 | Trailer tow right turn/stop lamps |
| 37 | 20 | Cargo area power point |
| 38 | 25 | Rear wiper motor, Washer pump (rear window wash) |
| 39 | 20 | Console power points (front and rear of console), Instrument panel power point (bench seat) |
| 40 | 20 | DRL relays, DRL foglamps, DRL headlamp relay coil, Headlamp switch (headlamps), Multifunction switch (flash-to-pass), BSM (autolamp headlamps relay), High beam relay coil, Fuse 25 (LH low beam), Fuse 23 (RH low beam) |
| 41 | 20 | Cigarette lighter, OBD II diagnostic connector |
| 42 | 10 | Trailer tow left turn/stop lamps |
| 101 | 30 | Starter motor relay, Starter motor solenoid |
| 102 | 30 | Ignition switch power |
| 103 | 30 | ABS/AdvanceTrac® with RSC module (pump motor) |
| 104 | 30 | LH 3rd row seat relay, LH 3rd row seat switch, LH 3rd row seat motor |
| 105 | 30 | Spare |
| 106 | 30 | Trailer tow battery charge relay, Trailer tow 7–way connector (battery charge) |
| 107 | 30 | Auxiliary A/C blower relay, Auxiliary A/C blower motor |
| 108 | 30 | Passenger seat motor switch |
| 109 | 30 | Driver seat motor switch (non-memory), Memory module, Power memory mirrors, Adjustable pedals switch and motor |
| 110 | 30 | Spare |
| 111 | 50 | Air suspension compressor, Air suspension compressor relay |
| 112 | 30 | ABS/AdvanceTrac® with RSC module (valves) |
| 113 | 30 | Front wiper motor, Washer pump (windshield wash) |
| 114 | 40 | Rear window defroster relay, Rear window defroster grid, Heated mirrors (Fuse 8) |
| 115 | 30 | Transfer case shift motor, 4×4 relays |
| 116 | 40 | Front blower motor relay, Front blower motor |
| 117 | 30 | RH 3rd row seat relay, RH 3rd row seat switch, RH 3rd row seat motor |
| 118 | 30 | Driver and passenger climate control seat module |
| 401 | 30 | Power windows (circuit breaker), Main window switch, Window motors, Window switches, Moonroof module |
| R01 | Starter relay: Starter motor solenoid | |
| R02 | Delayed accessory relay: Fuse 22, CB 401, Power windows, Switch backlighting, Radio, Moonroof, Flip windows, Navigation antenna amplifier | |
| R03 | Hi-beam relay: Fuse # 35, Hi-beam headlamps, Hi-beam indicator | |
| R04 | Rear window defrost relay: Fuse 8 (heated mirrors), Rear window defroster, Heated outside mirrors, Rear window defroster indicator (climate control head) | |
| R05 | Trailer tow battery charge relay: Trailer tow 7–wire connector (battery charge) | |
| R06 | Front blower relay: Front blower motor | |
| R201 | Trailer tow park lamp relay: Trailer tow 7–wire and 4–wire connectors (park lamps) | |
| R202 | Foglamp relay: Front foglamps | |
| R203 | PCM relay: Fuse 32, Fuse 34, PCM solenoids and sensors | |
| R301 | Trailer tow back-up lamp relay: Trailer tow 7–wire connector (back-up lamps) | |
| R302 | Heated PCV valve relay: Heated PCV valve | |
| R303 | Fuel pump relay: Fuel pump shut-off switch, PCM (fuel pump monitor), Fuel pump, Fuel pump driver module | |
| R304 | Battery saver relay: Roof rail lamps, Vanity mirror lamps, Map/Dome lamp, Glove box lamp, Cargo area lamp, Outside mirror puddle lamps, Instrument cluster (interior lamps) | |
| R305 | Horn relay: Dual note horn |
Understanding OBD2 in Your 2003 Ford Expedition
The year 2003 marks a significant point in automotive technology as OBD2 (On-Board Diagnostics II) systems became standard in vehicles sold in the USA. The 2003 Ford Expedition is equipped with an OBD2 port, typically located under the dashboard on the driver’s side. This port is essential for mechanics and car owners to retrieve diagnostic trouble codes (DTCs) using an OBD2 scanner.
While fuse issues are electrical problems, they can sometimes trigger your vehicle’s OBD2 system. For instance, a blown fuse related to the engine control unit (PCM) or transmission could result in fault codes that are detectable through the OBD2 port. Therefore, when diagnosing a problem in your 2003 Expedition, it’s wise to check both the fuse box and the OBD2 system.
How Fuses and OBD2 Work Together in Diagnostics
A systematic approach to diagnosing electrical problems in your 2003 Ford Expedition should involve these steps:
- Symptom Identification: Note the specific electrical malfunction (e.g., headlights not working, radio dead, etc.).
- Fuse Box Check: Consult the fuse diagram and inspect the fuses related to the malfunctioning component. Replace any blown fuses with the correct amperage.
- OBD2 Scan: If the issue persists after checking fuses, or if the problem is less obvious, use an OBD2 scanner to check for diagnostic trouble codes. These codes can provide clues about the system experiencing issues.
- Further Diagnosis: Based on the OBD2 codes and fuse checks, proceed with more detailed diagnostics, which might involve checking relays, wiring, and specific components.
In conclusion, understanding the 2003 Ford Expedition fuse box diagram is a fundamental step in automotive maintenance. Combined with knowledge of the OBD2 system, you can effectively troubleshoot and address electrical problems in your vehicle, ensuring its reliable operation. Remember to always consult your vehicle’s repair manual for detailed procedures and safety precautions.
