This guide provides fuse box diagrams for the 2017–2019 Ford F-250, F-350, F-450, and F-550 Super Duty trucks.
It helps you quickly locate and identify fuses and relays for various electrical components, making it easier to diagnose and fix electrical issues.
Table of Contents
2017-2019 Ford F-250/F-350/F-450/F-550 Fuse Box Diagram
The 2017–2019 Ford F-250, F-350, F-450, and F-550 Super Duty trucks have two fuse box layouts: the Power Distribution Box (under the hood) and the Passenger Compartment Fuse Panel (inside the cabin).
Power Distribution Box
1Micro fuse. 2M case fuse. 3J case fuse.
| Fuse or Relay Number | Fuse Rating | Protected Components |
| 1 | 20A1 | Powertrain control module. |
| 2 | 20A1 | Emissions – malfunction indicator lamp. |
| 3 | 20A1 | Cooling fan. A/C compressor. Engine brake. |
| 4 | 20A1 | Noise suppression cap. Mass air flow sensor. Emissions. Glow plugs. Urea. |
| 5 | 15A1 | Compressed natural gas fuel control module. Fuel sensor. |
| 6 | — | Not used. |
| 7 | — | Not used. |
| 8 | — | Not used. |
| 9 | — | Not used. |
| 10 | 15A1 | Heated exterior mirrors. |
| 11 | — | Compressed natural gas relay. |
| 12 | 40A2 | Heated rear window. |
| 13 | — | Not used. |
| 14 | — | Powertrain control module relay. |
| 15 | 20A1 | Horn. |
| 16 | 10A1 | A/C clutch relay power. |
| 17 | — | Rear heated window and heated mirrors relay. |
| 18 | — | Trailer park lamp relay. |
| 19 | — | Not used. |
| 20 | — | Supplemental air heater bank #1 relay. |
| 21 | — | Not used. |
| 22 | — | Not used. |
| 23 | — | Not used. |
| 24 | — | Cooling fan relay. Supplemental air heater bank #3 relay. |
| 25 | — | Glow plug module power relay. |
| 26 | — | Not used. |
| 27 | 30A2 | Trailer tow battery charge relay (if equipped). |
| 28 | — | Not used. |
| 29 | — | Run-start relay. |
| 30 | 10A1 | 4×4 module. |
| 31 | 5A1 | Adaptive cruise control. Run-start. |
| 32 | 5A1 | Anti-lock brake system module. Run-start. |
| 33 | 10A1 | Powertrain control module – ignition status power run. Run-start. Engine control module. Transmission control module. |
| 34 | 10A1 | Blind spot information system. Run-start. Front camera. Rear camera. |
| 35 | — | Not used. |
| 36 | — | Blower motor relay. |
| 37 | — | Trailer tow battery charge relay (only on non-trailer brake controller vehicles). |
| 38 | — | A/C compressor clutch relay. |
| 39 | — | Horn relay. |
| 40 | — | Supplemental air heater bank #2 relay. |
| 41 | 25A2 | Glow plugs. |
| 42 | 40A2 | Trailer tow lighting module (if equipped). |
| 43 | 40A2 | Front blower motor. |
| 44 | 50A3 | Voltage quality. Body control module power. |
| 45 | 60A3 | Active front steering. |
| 46 | 50A3 | Supplemental air heater bank #2. |
| 47 | 50A3 | Cooling fan. Supplemental air heater bank #3. |
| 48 | 50A3 | Body control module run power 1 bus. |
| 49 | 60A3 | Inverter. |
| 50 | 50A3 | Body control module run power 2 bus. |
| 51 | 60A3 | Body control module B+ feed. |
| 52 | 60A3 | Anti-lock brake system pump. |
| 53 | 50A3 | Supplemental air heater bank #1. |
| 54 | 30A3 | Trailer brake control module. |
| 55 | 30A3 | Climate controlled seat module. |
| 56 | 40A3 | Auxiliary lighting module. |
| 57 | 30A2 | Power running boards. |
| 58 | 30A2 | Compressed natural gas fuel control module relay. |
| 59 | 30A2 | Anti-lock brake system valve. |
| 60 | — | Not used. |
| 61 | 30A2 | Driver power seat. |
| 62 | 20A2 | Auxiliary power point #1 (instrument panel). |
| 63 | 30A2 | Starter motor. |
| 64 | 20A2 | Auxiliary power point #2. |
| 65 | 30A2 | Trailer tow lighting module (if equipped). |
| 66 | 20A2 | Auxiliary power point #3 (center console). |
| 67 | 30A2 | Passenger power seat. |
| 68 | 20A2 | Auxiliary power point #4 (USB charger, rear center console). |
| 69 | 25A2 | 4×4 module. |
| 70 | 20A2 | Auxiliary power point #5 (rear center console). |
| 71 | — | Not used. |
| 72 | 30A2 | Trailer tow left hand/right hand stop/turn (if equipped, not present with trailer brake controller). |
| 73 | — | Not used. |
| 74 | — | Not used. |
| 75 | 30A2 | Fuel pump. |
| 76 | — | Not used. |
| 77 | 30A2 | Wiper motor. |
| 78 | — | Not used. |
| 79 | 30A2 | Power sliding rear window. |
| 80 | 25A1 | 4×4 module. |
| 81 | 10A1 | 4×4 solenoid. |
| 82 | 10A1 | Power telescoping mirrors. |
| 83 | 20A1 | Rear heated seats. |
| 84 | 10A1 | Trailer tow backup lamps (if equipped). |
| 85 | — | Not used. |
| 86 | — | Not used. |
| 87 | — | Not used. |
| 88 | 10A1 | Multi contour seats. |
| 89 | — | Not used. |
| 90 | 10A1 | Spot light module. |
| 91 | 10A1 | Upfitter interface module. |
| 92 | — | Not used. |
| 93 | — | Not used. |
| 94 | 15A1 | Transmission control module. |
| 95 | 10A1 | Powertrain control module keep alive power. |
| 96 | 5A1 | Rain sensor. |
| 97 | 10A1 | Run/Start control for Auxiliary power point #5 |
| 98 | 10A 1 | Alternator sense. |
| 99 | 30A 1 | Trailer tow parking lamps. |
Passenger Compartment Fuse Panel
4Micro 2 fuse. 5Micro 3 fuse. 6Circuit breaker.
| Fuse or Relay Number | Fuse Rating | Protected Components |
| 1 | — | Not used. |
| 2 | 7.5A4 | Memory seat switch (lumbar power). |
| 3 | 20A4 | Driver door unlock relay. |
| 4 | 5A4 | Aftermarket electronic brake controller. Trailer brake controller Brake On/Off. Customer access circuits. |
| 5 | — | Not used. |
| 6 | — | Not used. |
| 7 | — | Not used. |
| 8 | 10A5 | Driver window switch mirror fold. |
| 9 | 10A5 | Brake On/Off / Pressure Switch. |
| 10 | — | Not used. |
| 11 | 5A5 | Combined sense security module. |
| 12 | 7.5A5 | Front climate control module. |
| 13 | 7.5A5 | Instrument cluster. Smart data link. Steering column control module. |
| 14 | 10A5 | Extended power restraints module. |
| 15 | 10A5 | Smart datalink connector power. |
| 16 | 15A4 | Tailgate release solenoid. |
| 17 | 5A5 | Head-up display. |
| 18 | 5A5 | Push button ignition switch. Ignition switch. Key inhibit. |
| 19 | 7.5A5 | Transmission control switch (tow/haul). Select Shift switch. |
| 20 | 7.5A5 | Active front steering module. |
| 21 | 5A5 | Head-up display. Humidity sensor. |
| 22 | 5A5 | Upfitter switch. Run/Start. PTO relays. |
| 23 | 10A4 | Accessory delay. Power windows. Moonroof. Power folding mirrors relay. Inverter. Window/moonroof switch illumination. |
| 24 | 20A4 | Central locking system relay. |
| 25 | 30A4 | Left-hand front smart window motor. Door zone module. |
| 26 | 30A4 | Right-hand front smart window motor. Door zone module. |
| 27 | 30A4 | Moonroof. |
| 28 | 20A4 | Sony amplifier – 10 channel. |
| 29 | — | Not used. |
| 30 | — | Not used. |
| 31 | 15A4 | Adjustable pedals switch. |
| 32 | 10A4 | SYNC. GPS module. Display. Radio frequency receiver. |
| 33 | 20A4 | Radio. |
| 34 | 30A4 | Run-start relay. |
| 35 | 5A4 | Extended power restraints module. |
| 36 | 15A4 | Lane keeping system. Automatic high beam control. Auto-dimming mirrors. Rear heated seats. Camera module. |
| 37 | 20A4 | Heated steering wheel. |
| 38 | 30A6 | Rear power window switch. |
Tip: Some high-amperage fuses may look slightly different depending on the model year and trim. Always verify the fuse type before replacing.
Fuse Replacement Tips / Safety Precautions
- Always disconnect the negative battery terminal before removing fuses.
- Never replace a blown fuse with a higher amp rating — this can damage wiring or cause a fire.
- Use a fuse puller or needle-nose pliers for safety.
- Label replaced fuses for future reference.
Frequently Asked Questions (FAQs)
Why does my cigarette lighter or power socket fuse keep blowing?
A repeatedly blown power socket fuse usually means there’s an overload, short, or incorrect fuse rating in the circuit.
Overload: High-power accessories like air compressors or inverters draw too much current.
Short circuit: Frayed or exposed wires touching metal surfaces.
Faulty adapters: Low-quality chargers or plugs pulling excess power.
Wrong fuse: A fuse rated below Ford’s recommended specification.
Why does the radio fuse keep blowing?
If the radio fuse keeps failing, it’s often due to wiring problems or excessive power draw.
Short circuit: Damaged or exposed wiring contacting metal parts.
Aftermarket equipment: Added amps or accessories overwhelming the circuit.
Incorrect fuse: Lower-rated fuse than specified by Ford.
Defective radio: Internal short or fault drawing too much current.
Voltage spikes: Irregular output from the alternator or battery.
Why does my light fuse keep blowing?
Frequent light fuse failures often trace back to wiring faults, bad bulbs, or modifications.
Short circuit: Wire insulation worn through and touching metal.
Bad bulb: Burned-out or shorted bulb creating excess load.
Faulty switch: Damaged or worn switch causing irregular current.
Aftermarket lighting: LED or upgraded fog lights exceeding circuit limits.
Why does the tail light fuse keep blowing?
A blown tail light fuse usually results from wiring or component issues.
Short circuit: Melted or exposed wires grounding out.
Bad or incorrect bulb: Using the wrong bulb type or a damaged one.
Defective switch: Malfunctioning tail light switch causing surges.
Wrong fuse rating: Fuse lower than Ford’s specified amperage.
Why does the horn relay fail on my F-250?
Horn relay issues typically stem from electrical problems or normal wear and tear.
Short circuit: Faulty wiring pushing too much current through the relay.
Aging components: Relay contacts or coil wearing out over time.
Voltage spikes: Sudden surges damaging the relay or nearby components.
