Learn about Ford F-250 / F-350 / F-450 / F-550 (2005-2007) fuse box and relay’s locations, functions, and maintenance tips for optimal vehicle electrical system.
If you drive a 2005-2007 Ford Super Duty truck and you’re dealing with malfunctioning power windows, a dead trailer brake controller, or dashboard warning lights that won’t quit, a blown fuse or bad relay could easily be the cause. Before scheduling a repair shop visit, learning where your Super Duty’s fuse boxes are located can help you pinpoint—and often solve—the problem yourself.
Fuses and relays play a vital role in protecting your truck’s electrical system. Fuses are designed to blow intentionally when a circuit draws too much current, preventing damage to wiring harnesses and sensitive components. Relays act as remote-controlled switches, using a small electrical signal to control higher-powered systems like your headlights, fuel pump, or heavy-duty cooling fan.
For owners of the F-250, F-350, F-450, and F-550 Super Duty trucks, understanding fuse box and relay locations is especially useful given how many of these vehicles are outfitted with aftermarket equipment, trailer wiring, and upfitter switches. This guide breaks down exactly where to find your fuse boxes and how to safely access them for troubleshooting or maintenance.
MUST READ: DYI – How to Check Car Fuses?
(2005-2007) Ford F-250 / F-350 / F-450 / F-550 fuse box and relay with Diagram
WARNING
- Never replace a fuse with one that has a higher amperage rating.
- A fuse with a too-high amperage could damage the electrical part and cause a fire.
- On no account should fuses be repaired (e.g. patched up with tin foil or wire) as this may cause serious damage elsewhere in the electrical circuit or cause a fire.
- If a fuse blows repeatedly, do not keep replacing it. Instead, have the cause for the repeated short circuit or overload tracked and fixed.
- Terminal and harness assignments for individual connectors will vary depending on vehicle equipment level, model, and market.
Ford F-250 / F-350 / F-450 / F-550 (2005-2007) fuse assignment
Ford F-250 / F-350 / F-450 / F-550 Year of production: 2005, 2006, 2007
Fuse Box Locations in the 2005-2007 Super Duty Trucks
These heavy-duty trucks are equipped with multiple fuse and relay locations to manage both standard vehicle systems and additional equipment often installed for work or towing purposes. You’ll typically find two main fuse boxes, along with additional relay panels depending on your truck’s configuration.
Engine Compartment Fuse Box (Power Distribution Box)
The primary fuse box is located in the engine bay, mounted near the battery on the driver’s side. Known as the Power Distribution Box, this unit houses high-amperage fuses and relays that control essential systems such as the headlights, engine cooling fan, ABS module, and glow plug relay (on diesel models).
To access this fuse box, make sure the engine is off and the key is removed from the ignition. Locate the large black plastic cover secured by clips or retaining tabs along the edges. On some trims, you may need to unscrew a few fasteners before lifting the cover away. Once removed, you’ll find a fuse and relay diagram printed on the underside of the cover, making it easy to match components to their corresponding fuse or relay.
Interior Fuse Box (Passenger Compartment)
The interior fuse panel is located inside the cab, on the driver’s side, beneath the dashboard near the kick panel area. This fuse box manages cabin electrical systems including the radio, power seats, interior lighting, power door locks, and dashboard instrumentation.
To access it, sit in the driver’s seat and look below the steering column near your left knee. The panel cover is typically secured with a latch or a couple of screws. Once opened, you’ll see the fuse layout along with a printed diagram on the inside of the cover, helping you quickly identify which fuse corresponds to which system.
Auxiliary Relay and Upfitter Switch Panel
Given that many Super Duty trucks are used for towing, plowing, or commercial applications, this generation often includes an auxiliary relay panel or upfitter switch panel. This is typically located either in the engine bay near the primary fuse box or under the dashboard close to the interior fuse panel, depending on the truck’s factory configuration.
This panel manages relays for aftermarket equipment such as trailer brake controllers, snow plow lights, or auxiliary power outlets. If your truck was ordered with upfitter switches from the factory, check your owner’s manual for the exact location, as placement can vary between single-rear-wheel and dual-rear-wheel (dually) models.
How to Safely Access and Work with Fuses and Relays
Safety comes first whenever you’re working with your truck’s electrical system. Always turn off the ignition and remove the key before opening any fuse box. If you’re planning to replace several fuses or work near the battery terminals, disconnecting the negative battery cable adds an extra layer of protection against short circuits or accidental electrical shocks.
When removing a fuse, use the plastic fuse-puller tool, usually clipped inside the fuse box cover. This tool is designed to grip the fuse securely without risking damage to the terminals or surrounding components. Avoid using metal tools like screwdrivers or pliers, which can cause sparks or accidental short circuits.
Relays require a slightly different technique since they’re plugged into sockets rather than snapped into place like fuses. Gently rock the relay from side to side while pulling upward to avoid bending the connector pins. If a relay feels stuck, check for a retaining clip or bracket before applying more force.
Identifying the Right Fuse or Relay
Every fuse and relay in your Super Duty’s fuse boxes is labeled with a number or letter that corresponds to a printed diagram, typically found on the inside of the fuse box cover or in your owner’s manual. This diagram identifies exactly which component each fuse or relay controls, from your power mirrors to your trailer brake system.
Before pulling any fuse, cross-reference the diagram with the physical fuse box to make sure you’re addressing the correct circuit. This step saves time and prevents unnecessary disruption to unrelated systems while troubleshooting.
A blown fuse is usually easy to identify—look for a discolored appearance or a visibly broken metal strip inside the clear plastic housing. Always replace a blown fuse with one of the same amperage rating. Using a higher-rated fuse can damage your truck’s wiring and create a potential fire hazard, so precision matters here.
Checking and Replacing Fuses in Ford F-250 / F-350 / F-450 / F-550
If electrical components in the vehicle are not working, a fuse may have blown. Blown fuses are identified by a broken wire within the fuse. Check the appropriate fuses before replacing any electrical components. To remove a fuse use the fuse puller tool provided on the fuse panel cover.
Location of Fuse Boxes
Passenger Compartment Fuse Panel:
The fuse panel is located below and to the left of the steering wheel by the brake pedal. Remove the panel cover to access the fuses. To remove the fuse panel cover, pull the panel downward by the finger slots on top of the panel. When the top clips of the panel disengage, let the panel fall easily.
Power Distribution Box:
The power distribution box is located in the engine compartment. The power distribution box contains high-current fuses that protect your vehicle’s main electrical systems from overloads.
Relays:
An auxiliary relay box is located in the left-hand front side of the engine compartment. This box contains relays for the Electronic Shift On the Fly (ESOF) system. Please see your authorized dealer for troubleshooting or service of these relays.
Fuse Box Diagrams
2005
Passenger Compartment Fuse Panel
List of fuses in the passenger compartment fuse panel (2005)
| № | A | Description |
|---|---|---|
| 1 | 15A* | Adjustable pedais |
| 2 | 10A* | Cluster |
| 3 | 10A* | Upfitter #3 |
| 4 | 20A* | Power point (Instrument panel) |
| 5 | 10A* | Upfitter #4 |
| 6 | – | Not used |
| 7 | 30A* | High beam headlamps, Flash-to-pass |
| 8 | 20A* | Back-up lamps |
| 9 | – | Not used |
| 10 | – | Not used |
| 11 | 20A* | Radio (Main) |
| 12 | 20A* | Cigar lighter, OBD II |
| 13 | 5A* | Power mirrors |
| 14 | – | Not used |
| 15 | – | Not used |
| 16 | – | Not used |
| 17 | 15A* | Exterior lamps |
| 18 | 20A* | Flasher, Brake On-Off (BOO) lamps |
| 19 | 10A* | Body Security Module (BSM) (Security) |
| 20 | 15A* | Trailer tow Electric Brake Controller (EBC) |
| 21 | 20A* | Heated seats |
| 22 | 20A* | Engine control |
| 23 | 20A* | Engine control (gasoline engine only)/Climate control (Diesel engine only) |
| 24 | 15A* | Tow haul, Blower relay, Electronic Automatic Temperature Control (EATC) |
| 25 | – | Not used |
| 26 | 10A* | Air bags |
| 27 | 15A* | Ignition switch RUN feed |
| 28 | 10A* | Trailer tow EBC logic |
| 29 | 10A* | Customer access |
| 30 | 15A* | High beam headlamps |
| 31 | 15A* | 4×4 |
| 32 | 5A* | Radio (start) |
| 33 | 15A* | Cluster, 4×4, Wipers |
| 34 | 10A* | BOO switch (Low current) |
| 35 | 10A* | Instrument cluster |
| 36 | – | Not used |
| 37 | 15A* | Horn |
| 38 | 20A* | Trailer tow park lamps |
| 39 | 15A* | Heated mirrors |
| 40 | 20A* | Fuel pump |
| 41 | 10A* | Instrument cluster |
| 42 | 15A* | Delayed accessory |
| 43 | 10A* | Fog lamps |
| 44 | – | Not used |
| 45 | 10A* | Ignition switch RUN/START feed |
| 46 | 10A* | Left-hand low beam headlamp |
| 47 | 10A* | Right-hand low beam headlamp |
| 48 | – | Not used |
| 101 | 30A** | Trailer tow EBC |
| 102 | 30A** | BSM (Door locks) |
| 103 | 30A** | Ignition switch |
| 104 | – | Not used |
| 105 | – | Not used |
| 106 | – | Not used |
| 107 | 20A** | Trailer tow battery charge |
| 108 | 30A** | Upfitter #1 |
| 109 | 30A** | Upfitter #2 |
| 110 | 30A** | Ignition switch |
| 111 | – | Not used |
| 112 | 30A** | Power seat (Driver) |
| 113 | 30A** | Starter |
| 114 | 30A** | Power seat (Passenger) |
| 115 | 20A** | Upfitter control |
| 116 | 30A** | Ignition switch |
| 210 | – | Not used |
| 211 | 1⁄2 ISO relay | Back-up lamps |
| 212 | – | Not used |
| 301 | Full ISO relay | Trailer tow battery charge |
| 302 | Full ISO relay | Powertrain Control Module (PCM) |
| 303 | – | Not used |
| 304 | – | Not used |
| 305 | Full ISO relay | Upfitter control |
| 306 | Full ISO relay | Delayed accessory |
| 307 | Full ISO relay | Starter |
| 601 | 30A Circuit breaker | Delayed accessory, Power Windows, Moonroof |
| 602 | – | Not used |
| * Mini fuse ** Cartridge fuse | ||
Power Distribution Box
List of fuses in the power distribution box (2005)
| № | A | Description |
|---|---|---|
| 1 | 30A* | Wipers |
| 2 | 40A* | Blower |
| 3 | 30A* | Electronic Shift on the Fly (ESOF) |
| 4 | – | Not used |
| 5 | 50A* | Injector Driver Module (IDM) (Diesel engine only) |
| 6 | – | Not used |
| 7 | 30A* | Horizontal Fuel Conditioner Module (HFCM) (Diesel engine only) |
| 8 | – | Not used |
| 9 | 20A** | Trailer tow turn signals |
| 10 | 10A** | Powertrain Control Module (PCM) keep alive power, Canister vent solenoid (gasoline engine only) |
| 11 | 10A** | Anti-lock Brake System (ABS) |
| 12 | 2A** | Brake pressure switch |
| 13 | 15A** | Daytime Running Lamps (DRL) |
| 14 | – | Not used |
| 15 | 15A** | IDM logic (Diesel engine only) |
| 16 | – | Not used |
| 17 | 10A** | A/C clutch |
| 18 | 10A** | IDM relay (Diesel engine only) |
| 19 | – | Not used |
| 20 | 10A** | Trailer tow back-up lamps |
| 21 | – | Not used |
| 22 | 60A*** | ABS (Coils) |
| 23 | 60A*** | ABS (Pump) |
| 201 | 1⁄2 ISO relay | Trailer tow right turn signal/stop lamp |
| 202 | 1⁄2 ISO relay | Trailer tow left turn signal/stop lamp |
| 203 | 1⁄2 ISO relay | A/C clutch |
| 204 | – | Not used |
| 205 | 1⁄2 ISO relay | DRL #1 |
| 206 | 1⁄2 ISO relay | DRL #2 |
| 301 | Full ISO relay | DRL #3 |
| 302 | Full ISO relay | HFCM |
| 303 | Full ISO relay | Blower |
| 304 | High-current relay | IDM (Diesel engine only) |
| * Cartdrige Fuse ** Mini Fuses *** Maxi fuse | ||
2006
Passenger Compartment Fuse Panel
List of fuses in the passenger compartment fuse panel (2006)
| № | A | Description |
|---|---|---|
| 1 | 15A* | Adjustable pedais |
| 2 | 10A* | Cluster |
| 3 | 10A* | Upfitter #3 |
| 4 | 20A* | Power point (Instrument panei) |
| 5 | 10A* | Upfitter #4 |
| 6 | Not used | |
| 7 | 30A* | High beam headlamps, Flash-to-pass |
| 8 | 20A* | Back-up lamps |
| 9 | – | Not used |
| 10 | – | Not used |
| 11 | 20A* | Radio (Main) |
| 12 | 20A* | Cigar lighter, OBD II |
| 13 | 5A* | Power mirrors |
| 14 | – | Not used |
| 15 | – | Not used |
| 16 | – | Not used |
| 17 | 15A* | Exterior lamps |
| 18 | 20A* | Flasher, Brake On-Off (BOO) lamps |
| 19 | 10A* | Body Security Module (BSM) (Security) |
| 20 | 15A* | Trailer tow Electric Brake Controller (EBC) |
| 21 | 20A* | Heated seats |
| 22 | 20A* | Engine control |
| 23 | 20A* | Engine control (gasoline engine only)/Climate control (Diesel engine only) |
| 24 | 15A* | Tow haul, Blower relay, Electronic Automatic Temperature Control (EATC) |
| 25 | – | Not used |
| 26 | 10A* | Airbags |
| 27 | 15A* | Ignition switch RUN feed |
| 28 | 10A* | Trailer tow EBC logic |
| 29 | 10A* | Customer access |
| 30 | 15A* | High beam headlamps |
| 31 | 15A* | Starter relay |
| 32 | 5A* | Radio (start) |
| 33 | 15A* | Cluster, 4×4, Wipers |
| 34 | 10A* | BOO switch (Low current) |
| 35 | 10A* | Instrument cluster |
| 36 | – | Not used |
| 37 | 15A* | Horn |
| 38 | 20A* | Trailer tow park lamps |
| 39 | 15A* | Heated mirrors |
| 40 | 20A* | Fuel pump |
| 41 | 10A* | Instrument cluster |
| 42 | 15A* | Delayed accessory |
| 43 | 10A* | Fog lamps |
| 44 | – | Not used |
| 45 | 10A* | Ignition switch RUN/START feed |
| 46 | 10A* | Left-hand low beam headlamp |
| 47 | 10A* | Right-hand low beam headlamp |
| 48 | – | Not used |
| 101 | 30A** | Trailer tow EBC |
| 102 | 30A** | BSM (Door locks) |
| 103 | 30A** | Ignition switch |
| 104 | – | Not used |
| 105 | – | Not used |
| 106 | – | Not used |
| 107 | 20A** | Trailer tow battery charge |
| 108 | 30A** | Upfitter #1 |
| 109 | 30A** | Upfitter #2 |
| 110 | 30A** | Ignition switch |
| 111 | – | Not used |
| 112 | 30A** | Power seat (Driver) |
| 113 | 30A** | Starter |
| 114 | 30A** | Power seat (Passenger) |
| 115 | 20A** | Upfitter control |
| 116 | 30A** | Ignition switch |
| 210 | – | Not used |
| 211 | 1⁄2 ISO relay | Back-up lamps |
| 212 | – | Not used |
| 301 | Full ISO relay | Trailer tow battery charge |
| 302 | Full ISO relay | Powertrain Control Module (PCM) |
| 303 | – | Not used |
| 304 | – | Not used |
| 305 | Full ISO relay | Upfitter control |
| 306 | Full ISO relay | Delayed accessory |
| 307 | Full ISO relay | Starter |
| 601 | 30A Circuit breaker | Delayed accessory, Power Windows, Moonroof |
| 602 | – | Not used |
| * Mini fuse ** Cartridge fuse | ||
Power Distribution Box
List of fuses in the power distribution box (2006)
| № | A | Description |
|---|---|---|
| 1 | 30A* | Wipers |
| 2 | 40A* | Blower |
| 3 | 30A* | Electronic Shift on the Fly (ESOF) |
| 4 | – | Not used |
| 5 | 50A* | Injector Driver Module (IDM) (Diesel engine only) |
| 6 | – | Not used |
| 7 | – | Not used |
| 8 | – | Shunt |
| 9 | 20A** | Trailer tow turn signals |
| 10 | 10A** | Powertrain Control Module (PCM) keep alive power, Canister vent solenoid (gasoline engine only) |
| 11 | 10A** | Anti-lock Brake System (ABS) |
| 12 | 2A** | Brake pressure switch |
| 13 | 15A** | Daytime Running Lamps (DRL) |
| 14 | – | Not used |
| 15 | 15A** | IDM logic (Diesel engine only) |
| 16 | – | Not used |
| 17 | 10A** | A/C clutch |
| 18 | 10A** | IDM relay (Diesel engine only) |
| 19 | – | Not used |
| 20 | 10A** | Trailer tow back-up lamps |
| 21 | – | Not used |
| 22 | 60A*** | ABS (Coils) |
| 23 | 60A*** | ABS (Pump) |
| 201 | 1⁄2 ISO relay | Trailer tow right turn signal/stop lamp |
| 202 | 1⁄2 ISO relay | Trailer tow left turn signal/stop lamp |
| 203 | 1⁄2 ISO relay | A/C clutch |
| 204 | – | Not used |
| 205 | 1⁄2 ISO relay | DRL #1 |
| 206 | 1⁄2 ISO relay | DRL #2 |
| 301 | Full ISO relay | DRL #3 |
| 302 | – | Not used |
| 303 | Full ISO relay | Blower |
| 304 | High-current relay | IDM (Diesel engine only) |
| * Cartridge Fuse ** Mini Fuses *** Maxi fuse | ||
2007
Passenger Compartment Fuse Panel
List of fuses in the passenger compartment fuse panel (2007)
| № | A | Description |
|---|---|---|
| 1 | 15A* | Adjustable pedals |
| 2 | 10A* | Cluster |
| 3 | 10A* | Upfitter #3 |
| 4 | 20A* | Power point (Instrument panel) |
| 5 | 10A* | Upfitter #4 |
| 6 | – | Not used |
| 7 | 30A* | High beam headlamps, Flash-to-pass |
| 8 | 20A* | Back-up lamps |
| 9 | – | Not used |
| 10 | – | Not used |
| 11 | 20A* | Radio (Main) |
| 12 | 20A* | Cigar lighter, OBD II |
| 13 | 5A* | Power mirrors |
| 14 | – | Not used |
| 15 | – | Not used |
| 16 | – | Not used |
| 17 | 15A* | Exterior lamps |
| 18 | 20A* | Flasher, Brake On-Off (BOO) lamps |
| 19 | 10A* | Body Security Module (BSM) (Security) |
| 20 | 15A* | Trailer tow Electric Brake Controller (EBC) |
| 21 | 20A* | Heated seats |
| 22 | 20A* | Engine control |
| 23 | 20A* | Engine control (gasoline engine only)/Climate control (Diesel engine only) |
| 24 | 15A* | Tow haul, Blower relay, Electronic Automatic Temperature Control (EATC) |
| 25 | – | Not used |
| 26 | 10A* | Airbags |
| 27 | 15A* | Ignition switch RUN feed |
| 28 | 10A* | Trailer tow EBC logic |
| 29 | 10A* | Customer access |
| 30 | 15A* | High beam headlamps |
| 31 | 15A* | Starter relay |
| 32 | 5A* | Radio (start) |
| 33 | 15A* | Cluster, 4×4, Wipers |
| 34 | 10A* | BOO switch (Low current) |
| 35 | 10A* | Instrument cluster |
| 36 | – | Not used |
| 37 | 15A* | Horn |
| 38 | 20A* | Trailer tow park lamps |
| 39 | 15A* | Heated mirrors |
| 40 | 20A* | Fuel pump |
| 41 | 10A* | Instrument cluster |
| 42 | 15A* | Delayed accessory |
| 43 | 10A* | Fog lamps |
| 44 | – | Not used |
| 45 | 10A* | Ignition switch RUN/START feed |
| 46 | 10A* | Left-hand low beam headlamp |
| 47 | 10A* | Right-hand low beam headlamp |
| 48 | – | Not used |
| 101 | 30A** | Trailer tow EBC |
| 102 | 30A** | BSM (Door locks) |
| 103 | 30A** | Ignition switch |
| 104 | – | Not used |
| 105 | – | Not used |
| 106 | – | Not used |
| 107 | 20A** | Trailer tow battery charge |
| 108 | 30A** | Upfitter #1 |
| 109 | 30A** | Upfitter #2 |
| 110 | 30A** | Ignition switch |
| 111 | – | Not used |
| 112 | 30A** | Power seat (Driver) |
| 113 | 30A** | Starter |
| 114 | 30A** | Power seat (Passenger) |
| 115 | 20A** | Upfitter control |
| 116 | 30A** | Ignition switch |
| 210 | – | Not used |
| 211 | 1⁄2 ISO relay | Back-up lamps |
| 212 | – | Not used |
| 301 | Full ISO relay | Trailer tow battery charge |
| 302 | Full ISO relay | Powertrain Control Module (PCM) |
| 303 | – | Not used |
| 304 | – | Not used |
| 305 | Full ISO relay | Upfitter control |
| 306 | Full ISO relay | Delayed accessory |
| 307 | Full ISO relay | Starter |
| 601 | 30A Circuit breaker | Delayed accessory, Power Windows, Moonroof |
| 602 | – | Not used |
| * Mini fuse ** Cartridge fuse | ||
Power Distribution Box
List of fuses in the power distribution box (2007)
| № | A | Description |
|---|---|---|
| 1 | 30A* | Wipers |
| 2 | 40A* | Blower |
| 3 | 30A* | Electronic Shift on the Fly (ESOF) |
| 4 | – | Not used |
| 5 | 50A* | Injector Driver Module (IDM) (Diesel engine only) |
| 6 | – | Not used |
| 7 | – | Not used |
| 8 | – | Shunt |
| 9 | 20A** | Trailer tow turn signals |
| 10 | 10A** | Powertrain Control Module (PCM) keep alive power, Canister vent solenoid (gasoline engine only) |
| 11 | 10A** | Anti-lock Brake System (ABS) |
| 12 | 2A** | Brake pressure switch |
| 13 | 15A** | Daytime Running Lamps (DRL) |
| 14 | – | Not used |
| 15 | 15A** | IDM logic (Diesel engine only) |
| 16 | – | Not used |
| 17 | 10A** | A/C clutch |
| 18 | 10A** | IDM relay (Diesel engine only) |
| 19 | – | Not used |
| 20 | 10A** | Trailer tow back-up lamps |
| 21 | – | Not used |
| 22 | 60A*** | ABS (Coils) |
| 23 | 60A*** | ABS (Pump) |
| 201 | 1⁄2 ISO relay | Trailer tow right turn signal/stop lamp |
| 202 | 1⁄2 ISO relay | Trailer tow left turn signal/stop lamp |
| 203 | 1⁄2 ISO relay | A/C clutch |
| 204 | – | Not used |
| 205 | 1⁄2 ISO relay | DRL #1 |
| 206 | 1⁄2 ISO relay | DRL #2 |
| 301 | Full ISO relay | DRL #3 |
| 302 | – | Not used |
| 303 | Full ISO relay | Blower |
| 304 | High-current relay | IDM (Diesel engine only) |
| * Cartridge Fuse ** Mini Fuses *** Maxi fuse | ||
Conclusion
Knowing the fuse box and relay locations in your 2005-2007 Ford F-250, F-350, F-450, or F-550 Super Duty truck gives you the tools to troubleshoot common electrical issues confidently, whether you’re dealing with towing equipment, upfitter switches, or standard cab electronics. From the engine bay’s Power Distribution Box to the auxiliary relay panel, understanding these locations makes diagnosing and fixing problems much more manageable.
That said, if you’ve checked the relevant fuses and relays and your electrical issue persists, it’s a good idea to consult a qualified mechanic, especially given the added complexity of aftermarket equipment often installed on these work-ready trucks. Persistent electrical problems can point to deeper wiring issues that require professional diagnostic tools to resolve safely and correctly.
