The 2020-2022 Ford F-550 Super Duty uses the updated P558-generation electrical layout. Most fuse positions are shared across these model years, but several assignments and spare slots changed in 2021 and 2022. The variations are retained in the tables rather than treating the three model years as completely identical.
On the F-550, pay particular attention to trailer charging and braking, four-wheel drive, the 6.7-liter Power Stroke diesel and the upfitter circuits. A rollback bed, dump body, lift or other specialist conversion may have additional protection supplied by the body builder outside the original Ford panels.
Where are the fuse boxes in a 2020-2022 Ford F-550?
Under the hood: the engine compartment power distribution box houses high-current protection for the powertrain, ABS, steering, trailer connections, four-wheel drive, seats and accessories. Open the hood, find the covered fuse box and release its retainers to access the numbered positions.
Inside the cab: the interior fuse panel is behind the trim cover on the right-hand side of the front passenger footwell. Carefully remove this access cover to inspect fuses for the radio, SYNC, doors, windows, upfitter switches and trailer brake controller.
Engine compartment fuse box
| Position | Amperage [A] | Protected circuit / function |
|---|---|---|
| 1 | 20 | Power point 4 |
| 2 | 20 | Power point 3 |
| 3 | 10 | Spot lamp module |
| 4 | 10 | Four-wheel-drive vacuum solenoid |
| 5 | 40 | Active front steering system |
| 6 | 10 | Snowplow, if equipped |
| 7 | 30 | Trailer battery charging |
| 8 | 10 | ABS module |
| 9 | 10 | Electric power steering module |
| 10 | 30 | Trailer parking lamps |
| 11 | 20 | Horn |
| 12 | 30 | Torque Overlay system |
| 13 | 30 | Power sliding rear window |
| 14 | 40 | BCM battery feed 1 |
| 15 | 30 | Power passenger seat |
| 16 | 10 | PCM and TCM |
| 17 | 10 | BLIS blind spot monitoring system |
| 18 | 10 | Four-wheel-drive module |
| 19 | 5 | Adaptive cruise control |
| 20 | 15 | Heated mirrors |
| 21 | 40 | Heated rear window |
| 22 | 10 | OBD diagnostic module and Smart Data Link Connector |
| 23 | 15 | Transmission control module, TCM |
| 24 | 30 | Power driver seat |
| 25 | 25 | Voltage quality module |
| 26 | 30 | Trailer battery charging |
| 27 | 20 | Heated rear seats |
| 28 | 25 | Diesel: glow plugs. Gasoline: not used |
| 29 | 40 | Electric power steering motor |
| 30 | 10 / 10 / – | 2020: heated windshield wiper park area, 10 A. 2021: spare or unused position, 10 A. 2022: not used |
| 31 | 20 | Power point 5 |
| 32 | 25 | Four-wheel-drive module |
| 33 | 10 | Alternator sense signal, circuit 2 |
| 34 | 50 | Gasoline: electric cooling fan. Diesel: auxiliary air heater |
| 35 | 20 | Power point 2 |
| 36 | 20 | Power point 1 |
| 37 | 60 | ABS pump |
| 38 | 60 | Power inverter |
| 39 | 25 | Four-wheel-drive module |
| 40 | 30 | Starter solenoid |
| 41 | 10 | Tailgate release solenoid |
| 42 | 40 | Blower motor |
| 43 | 10 | Trailer reversing lamps |
| 44 | 40 | Trailer lighting module |
| 45 | 30 | ABS valves |
| 46 | 30 | CNG module power supply, if equipped |
| 47 | 50 | Diesel: auxiliary air heater. Gasoline: not used |
| 48 | 50 | Diesel: auxiliary air heater. Gasoline: not used |
| 49 | – | Not used |
| 50 | 30 | Heated and ventilated seats |
| 51 | 20 | PCM module |
| 52 | 15 | Gasoline: CNG, if equipped. Diesel: fuel rail pressure relief valve control |
| 53 | 20 | Gasoline: EGR stepper motor and UEGO sensors. Diesel: EGR cooler bypass, DEF pump controller and oxygen sensors |
| 54 | 20 | A/C clutch relay feed and fan clutch |
| 55 | 5 | Rain sensor |
| 56 | 30 | Windshield wipers |
| 57 | 10 | Upfitter interface module |
| 58 | 10 | Alternator sense signal |
| 59 | 30 | Power running boards |
| 60 | 40 | BCM battery feed 2 |
| 61 | 10 | Power telescoping mirror motors |
| 62 | 40 | Trailer brake controller and auxiliary electric brake connection |
| 63 | 15 | Multicontour seats |
| 64 | 20 | Gasoline: ignition coil. Diesel: glow plug module, NOx module and DEF level and quality sensor |
| 65 | 30 | Fuel pump |
| 66 | 10 | Air-conditioning clutch solenoid |
| 67 | 40 | Auxiliary lighting module |
| 68 | 10 | PCM module |
| 69 | 60 | BCM power supply |
| 70 | 30 | Trailer stop lamps and turn signals |
The earlier F-550 generation has a different fuse assignment. The 2023 Ford F-250 diagram also belongs to the newer P708 Super Duty family, but should not be used as a substitute for the F-550 P558 table.
Passenger compartment fuse panel
| Position | Amperage [A] | Protected circuit / function |
|---|---|---|
| 1 | – | Not used |
| 2 | 10 | Driver door switch assembly and power sliding rear window switch |
| 3 | 7.5 | Seat memory switch, lumbar support motor and wireless charging module |
| 4 | – / 20 | 2020: not used. 2021-2022: spare or unused position, 20 A |
| 5 | – | Not used |
| 6 | 10 | Telescoping mirror switch and front power window switch |
| 7 | 10 | Brake on/off switch |
| 8 | 5 | Built-in modem |
| 9 | 5 | Integrated sensor module |
| 10 | – | Not used |
| 11 | – | Not used |
| 12 | 7.5 | OBD diagnostic module, Smart Data Link Connector and HVAC module |
| 13 | 7.5 | Steering column control module and instrument cluster |
| 14 | – / 15 | 2020: not used. 2021-2022: spare or unused position, 15 A |
| 15 | 15 | SYNC and display |
| 16 | – | Not used |
| 17 | 7.5 | Active steering module and parking aid module |
| 18 | 7.5 | Drive mode switch and SelectShift |
| 19 | 5 | Head-up display |
| 20 | 5 | Ignition switch and key interlock solenoid |
| 21 | 5 | Head-up display and cabin temperature/humidity sensor |
| 22 | 5 | Upfitter switches |
| 23 | 30 | Driver front door module |
| 24 | 30 | Sunroof |
| 25 | – / 20 | 2020: not used. 2021-2022: spare or unused position, 20 A |
| 26 | 30 | Passenger front door module |
| 27 | – / 30 | 2020: not used. 2021-2022: spare or unused position, 30 A |
| 28 | 30 | Audio amplifier |
| 29 | 15 | Adjustable pedal switch |
| 30 | 5 | Brake on/off signal for trailer brake controller and customer-access circuits |
| 31 | 10 | Remote Keyless Entry |
| 32 | 20 | Radio |
| 33 | – | Not used |
| 34 | 30 | Run/start relay |
| 35 | – / 5 | 2020: not used. 2021-2022: spare or unused position, 5 A |
| 36 | 15 | Camera module, lane-keeping system, auto-dimming mirror and heated rear seats |
| 37 | 20 | Heated steering wheel |
| 38 | 30 | Power window circuit breaker |
What changed between model years 2020, 2021 and 2022?
The most obvious example is under-hood position 30. In 2020 it is a 10 A fuse for the heated windshield wiper park area; in 2021 it is a 10 A spare/unused position; and in 2022 Ford lists it as unused. From 2021, the cabin panel also lists spare or unused fuse locations at positions 4, 14, 25, 27 and 35. These are not newly powered accessories.
Trailer circuits, upfitters and the 6.7 Power Stroke
Trailer malfunctions may involve several independent circuits. Under-hood positions 7 and 26 handle trailer battery charging, 10 the trailer parking lamps, 43 the reverse lamps, 44 the trailer lighting module, 62 the electric trailer brake controller and 70 the trailer stop and turn lamps. Interior position 30, rated at 5 A, supplies the brake on/off signal to the trailer brake controller.
On the 6.7-liter Power Stroke diesel, different protection applies to glow plugs, the glow-plug module, DEF components and EGR-related devices. Under-hood position 57 is a 10 A fuse associated with the upfitter interface module. Specialist body equipment may use additional fuses fitted by its installer.
For the later generation, use the 2023 Ford F-550 fuse box guide. The layouts must not be interchanged.
2020-2022 Ford F-550 fuse box FAQ
Do 2020, 2021 and 2022 F-550 trucks have exactly the same fuses?
No. The basic architecture is shared, but several entries differ by year. The tables retain those differences rather than publishing three near-duplicate guides.
Where is the trailer brake controller fuse?
Its main 40 A feed is under the hood at position 62. In the interior panel, position 30 contains the separate 5 A brake on/off signal fuse.
Could a commercial body have additional fuses?
Yes. Equipment installed by the manufacturer of a recovery truck, dump body or lifting system may have its own fuse, relay or circuit breaker near the battery, frame or an auxiliary distribution box.
What does engine compartment position 28 protect?
On diesel models, it is a 25 A fuse associated with the glow plugs. The position is not used on gasoline versions.