Mercedes W140 is an S-class model of the German brand Mercedes Benz, which was produced in 1991, 1992, 1993, 1994, 1995, 1996, 1997 and 1998. During this time, it underwent restyling. In this publication, you will find a description of the fuses and relays of the Mercedes 140 with block diagrams and their locations. Let’s highlight the fuse responsible for the cigarette lighter.
The execution of the blocks and the purpose of the elements in them may differ from the one presented and depends on the year of manufacture and the level of equipment of your Mercedes 140. Check the information presented with your diagrams.
Example diagram from the block cover
Blocks under the hood
Fuse and relay box
The main fuse and relay box is located on the left side next to the pillar and is covered with a protective cover.
Description of fuses
| 1 | Not connected |
| 2 | 30A Auxiliary Air Conditioner Fan Relay |
| 3 | 30A Windscreen Wiper Motor (09/95) |
| 4 | 40A Windscreen Wiper Motor (08/95) |
| 5 | 40A Rear fuse block pre-fuse (in luggage compartment) |
| 6 | 40A Rear window heating (except Coupe) – up to 1995, from 09/95 AIR pump, DRL daytime running light |
| 7 | 10A Up to 1992 headlight lens cleaners/since 1993 not connected |
| 8 | 7.5A Left Parking Light, Right Tail Light, Left Side Light |
| 9 | 7.5/15A Right parking light, Right rear side light, Number plate light, Headlamp lens cleaners, Exterior lighting switch (since 1993), Diode matrix engine speed increase (since 1996), Instrument cluster (since 1994), Cigarette lighter |
| 10 | 7.5A Rear Fog Light |
| 11 | 7.5A Low beam left headlight |
| 12 | 7.5A Right low beam headlight |
| 13 | 7.5A Left headlight high beam/high beam indicator lamp |
| 14 | 7.5A Right headlight high beam/high beam indicator lamp |
| 15 | 15A SRS Airbag Malfunction Indicator Lamp, Windscreen Wiper Relay, Combination Relay, High Beam Warning Switch, Washer Fluid Pump, Rear Window Defogger Switch, Rain Sensor (from 09/1995), Seat Belt Adjuster, Vanity Mirrors |
| 16 | 10A Cigarette Lighter , Glove Box Light, Starter Interlock Relay Module (since 1994) |
| 17 | 20A Ignition cut-off relay, Radio (up to 08/1995), after – steering column angle sensor, Non-proprietary reader connection socket, Diagnostic connector DLC, Diagnostic module (OBD II), Instrument cluster, Vanity mirror light, Direction indicator, Hazard warning switch, Interior light |
| 18 | 15A K/V, Aux Fan Relay Module |
| 19 | 7.5A Daytime Running Light DRL, Spark Plugs, Pre-Channel Timer Relay Module, Base Module, Seat Belt Warning Lamp (from 09/1995) |
| 20 | 10A A/C Push Button Control Module, A/C Compressor, Kickdown Switch, Purge Control Valve |
| 21 | 20A Windscreen Washer Nozzles, Electrically Heated Rear View Mirrors, Transmission Oil Cooler, A/C Control Unit |
| 22 | 7.5A up to 0.8/1995: Ignition/start switch, Audio system, Seat belt warning lamp module, Restraint system adjustment, Combination relay, Heated front seats, Heated rear seats, from 09/1995: Not connected |
| 23 | 7.5A Injectors, Instrument Cluster, Thermostat Switch, Ignition/Start Switch, Glow/Start Switch, Brake Light Switch, Center High Level Brake Light |
| 24 | 7.5A Mirror with automatic day/night mode switching, Basic module, Purge control valve, Instrument cluster, Exterior lamp condition monitoring module, Interior lighting, Electronic air mixing pump clutch (engine 603), Brake light switch, Seat belt warning module, DRL daytime running light, Engine control module (HFM-SFI engines) |
| 25 | 15A Turn Signal/Hazard Flasher Relay, Fan Relay Module, Starter/Reverse Light Circuit Open Switch, Reverse Lights, Shift Solenoids (SW) |
| 26 | 10A Fog lights |
| 27 | Not connected |
| 28 | 7.5A Automatic Antenna |
| 29 | 15A Front Seat Heating Control Module |
| 30 | 20A Left and right seat position memory, driver ergonomic parameter memory: Steering column adjustment, Rear view mirror adjustment, Electronic steering column adjustment |
| 31 | 30A Rear Power Bench Seat, Left Rear Power Seat, Rear Head Restraint |
| 32 | 7.5/30A Electric rear seat right, rear seat head restraint (Coupe) |
| 33 | Not connected |
| 34 | 7.5A Front Seat Heater Control Module, Rear Window Defogger, Relay Module (Coupe), Seat Belt Extender |
| 35 | 7.5A/15A Rear Window Sunshade, Comfort System |
| 36 | 10A Push Button Control Module K/V |
| 37 | 30A Left Front Seat Electric Drive |
| 38 | 30A Left Front Seat Electric Drive |
| 39 | Not connected |
| 40 | 30A Right Front Seat Electric Drive |
| 41 | 30A Right Front Seat Electric Drive |
Fuse number 16 is responsible for the front cigarette lighter. And for the rear one, there is a fuse in the block in the trunk.
Relay diagram
Designation
- R1 – Combined relay (windscreen wipers, rear window heating, warning lights and towing hitch)
- R2 – Reserve
- R3 – Starter interlock relay
- R4 – Horn relay (signal)
- R5 – High pressure/return pump relay
- R6 – Comfort equipment relay
- R7 – Headlight washer relay
Additional block
It is located on the right side under the hood and is also covered by a protective cover.
There may be additional elements responsible for:
- Electronic Stability Program (ESP)/Speed Sensitive Power Steering (SPS) Control Module
- Traction Control System (ASR) Control Module
- Front Seat Heating Control Module (under right rear seat – do not confuse with Rear Seat Heating Control Module – check via wiring harness)
- Transmission Control Module (TCM)
- Engine Control Module (ECM ME-SFI)
and other elements.
Block in the trunk
In the luggage compartment, on the right, behind the trim, there is another block with fuses and relays.
Purpose
| 1 | 15A Rear A/C |
| 2 | 7.5A ATA Anti-Theft Alarm Control Module, IRCL Infrared Control Module, Starter Lock Relay Module (1993), Rear Seat Heater Control Module |
| 3 | 20A Rear Cigarette Lighter , Central Locking, PSE Control Module, Door Closer |
| 4 | 7.5A Rear Vanity Mirror (before 1994) |
| 5 | 30A Electric window lifter |
| 6 | 30A Electric window lifter |
| 7 | 7.5/20A Rear Vanity Mirror Light (up to 08/1995), Seat Belt Extender Control Module (Coupe) |
| 8 | 20A Rear Cigarette Lighter |
| 9 | 30A Door Closer |
| 10 | 7.5A Cell Phone |
| 11 | 20A Power Window Control Module, Cargo Compartment Light, Rear Interior Light, Rear Reading Light, Rear Door Opener Light, PSE Control Module, Interior Single Lock Switch |
| 12 | 20A Rear Seat Heating Control Module |
| 13 | 30A Fuel Pump Relay Module |
| 14 | 25A Electric Sunroof Panel Drive |
| 15 | 25A ATA Anti-Theft Alarm Control Module, IRCL Infrared Control Module, Rear Headrests |
| 16 | 30A Tuner Amplifier, Audio Amplifier, Radio Receiver |
| 17 | Rear window heating |
There may be two relays installed nearby. The left one is the fuel pump relay, and the right one is the rear window heating relay.
Above the fuse box are installed: the comfort equipment control module, and next to it the anti-theft system control module (not to be confused with the anti-theft driver identification system control module, which is located under the instrument cluster on the steering column support bracket)).