Mercedes-Benz C-Class W205/S205/C205/A205 (2014-2021) – Fuse Box and Relay Diagrams

Mercedes-Benz C-Class 205 series (2014-2021) covers the W205 saloon, S205 estate, extended-wheelbase V205, C205 coupe and A205 cabriolet. Equipment and electrical circuits differ between body types, petrol, diesel, BlueTEC, Hybrid and AMG versions, and between early and facelifted cars.

The model has fuse and relay assemblies in the dashboard, engine bay, front passenger footwell and luggage compartment, as well as two high-current distribution blocks. Before replacing a fuse, identify the vehicle configuration and follow its original Mercedes fuse assignment card. Ratings listed with a slash are installation alternatives, not interchangeable sizes.

Where are the Mercedes W205 fuse boxes?

Dashboard fuse panel: turn the ignition off, open the relevant front door and carefully release the dashboard side access cover to reach the F200-F220 panel. Its exact orientation and access trim may vary with left- or right-hand drive and equipment.

Engine compartment: open the bonnet and locate the front fuse and relay carrier beneath its protective electrical cover. Avoid allowing moisture into the open housing. The F100-F129A group includes the front wiper, horn, starter, ESP and other engine or body circuits.

Front passenger footwell: move the front passenger seat rearward where necessary, lift or remove the footwell trim and access panel, then locate the F301-F323 and MF fuse carriers. Do not pull wiring or disassemble SRS-related components while investigating ordinary fuses.

Luggage compartment: open the boot or estate tailgate and fold back the side access trim to expose the rear SAM and its relay carrier. Trim access differs for the saloon, estate, coupe and cabriolet, so check the fitted layout. High-current pre-fuses are in separate assemblies and are not normal user-serviceable mini fuses.

For the preceding generation, use the separate Mercedes W204 fuse diagrams; the W204 and W205 have different fuse numbering and SAM architecture.

Common W205 fuses at a glance

This quick reference lists the most frequently checked positions and their ratings for the documented installation. Verify the applicable body and model year in the full tables.

Dashboard end fuse box F200-F220

The dashboard fuse carrier includes the front SAM supply, climate control, electronic ignition, steering systems, SRS and various market-specific modules. Several positions apply only to AMG or A205 cabriolet variants.

Dashboard relay F

Engine compartment fuse box F100-F129A and relays

This box includes the front wiper, headlamps, starter, horn, engine control and air-suspension circuits. AMG variants can have higher amperages on terminal 87 circuits. Hybrid versions use several additional positions, which should never be confused with ordinary 12 V fuse replacement.

Engine compartment relay positions G-R

Front wipers not working: inspect F109 (30 A). For LED headlight faults, check the equipped variant of F108 and F110 (20 A each). The horn circuit is on F115 (15 A). Engine-specific modules and relay functions must be checked against the individual car.

Front passenger footwell fuse box F301-F323 and MF positions

Use this box for seat and door controllers, DIRECT SELECT, COMAND, panoramic roof equipment, cameras, parking systems, radar, head-up display, AIRMATIC and selected Hybrid modules. The MF sub-groups are included in the same complete table.

Rear SAM and luggage compartment fuses F400-F467

Mercedes used more than one rear SAM arrangement. The original fuse card takes priority when identifying the exact version. The full table keeps the BlueTEC AdBlue positions, auxiliary outlet circuits, fuel controller, trailer supply and S205/C205/A205 body-style differences.

Rear SAM variant 1

Rear SAM variant 2

Rear SAM relays S-ZR3

The front cabin 12 V outlet normally uses F446 (15 A), and the rear console outlet uses F447 (15 A). The estate’s luggage area socket is listed as F445 (15 A). F442 (25 A) supplies fuel system control, while the BlueTEC AdBlue group is F400-F402. F463 supplies the heated rear glass on saloon and estate vehicles but has a different body circuit on coupe and cabriolet versions.

Interior high-current pre-fuse distribution

This distribution assembly supplies the blower, rear electrical modules, diesel heater and other high-load circuits. High-current fuse links should only be serviced following the correct vehicle electrical isolation procedure.

Engine compartment high-current pre-fuse block

Two versions of the front high-current assembly are documented. The table includes alternator, main module, cooling-fan, power-steering and ESP protection plus Hybrid-only connection positions.

Pre-fuse layout variant 1

Pre-fuse layout variant 2

Practical troubleshooting and production differences

Dead power socket: check the corresponding rear SAM fuse F446, F447 or estate-only F445, then inspect the socket and connected devices. Audio or COMAND not starting: inspect F322 (20 A) and the applicable display / multimedia subfuses in the passenger footwell.

Heated rear window not working: check the correct F463 allocation for W205, S205 or V205, and the rear-window heater relay T. Coupe and cabriolet installations can use this numbered position differently.

Repeated electrical failures: do not simply fit a larger fuse. Check for a short circuit, poor grounding, wiring damage or a failed consumer. In Hybrid models high-voltage connections require manufacturer-approved safety procedures and qualified personnel; never open them as if they were regular 12 V circuits.

Mercedes revised the W205 throughout production, including the 2018 facelift. Body type, engine code, Hybrid equipment, AMG packages, market and actual build date determine the final fuse assignment.