Mercedes-Benz 124 – a series of business-class passenger cars, produced in 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996 with both diesel and gasoline engines with various body styles (sedan, station wagon, coupe, convertible). During this time, the model has undergone restyling 2 times. In this publication you will find a description of the fuses and relays of the Mercedes 124 with block diagrams, their locations and photo examples of their execution. Let’s highlight the cigarette lighter fuse.
Fuse and relay block
Under the hood, the main fuse and relay block is located on the left side of the engine compartment and consists of two sections (fuses and relays).
Check the current designation of the elements with your diagram on the roof of the unit, as it may differ from the one presented and depends on the year of manufacture, equipment level and delivery region of your car.
| № | A | Description |
|---|---|---|
| 1 | 16 | Glove box light |
| Cigarette lighter | ||
| Rear window heating button | ||
| Rear window wiper and washer | ||
| Radio | ||
| Orthopedic seat back (124 545: 1500, 1600, 2100, 2200, 2700) | ||
| Electric headrests (124 545: 0700, 0900, 1500, 2100, 2200) | ||
| Seat belt feed system (124 545 2700) | ||
| 2 | 16 | Windshield wiper and washer |
| Headlight wiper relay (Kl. 86) | ||
| High beam headlight alarm circuit | ||
| Comfort system power relay (Kl. 86) | ||
| Window lift relay (Cl. 86) (124 545: 0700, 0900, 1300, 1600, 2200, 2500) | ||
| 3 | 8 | Right side light |
| Headlight cleaners (124 545: 0600, 0700, 0900) | ||
| License plate lighting | ||
| Instrument cluster illumination | ||
| Heater control lights | ||
| Warning buzzer (124 545: 0600, 1000, 1200, 1500, 2100, 2500, 2700) | ||
| 4 | 8 | Front fog lights |
| Rear fog light | ||
| 5 | 8 | Brake light bulbs |
| Instrument combination | ||
| Front interior lighting lamp | ||
| Outdoor lighting lamp fault indicator | ||
| Cruise control | ||
| Tachometer | ||
| Trailer control unit (124 545: 1200, 1500, 2100, 2700) | ||
| Roof control unit (124 545 2700) | ||
| Roof control button (124 545 2700) | ||
| 6 | 8 | Turn signals |
| Sound signal | ||
| Outdoor temperature sensor | ||
| On-board computer (123 545 1500) | ||
| Roof control unit (124 545 2700; DE: Ausloesegeraet Ueberrollbuegel) | ||
| 7 | 8/16 | Reverse lights |
| Heating appliance valve | ||
| Water pump | ||
| Engine cooling system fan | ||
| Windshield washer jet heating | ||
| Climate control unit | ||
| Auxiliary fan relay (Kl. 86) | ||
| Automatic transmission control unit | ||
| Internal heater fan sensor | ||
| Air conditioner compressor | ||
| Ignition valve switch off (124 545: 0600, 1000, 1200, 1500, 2100) | ||
| 8 | 8 | Left side light |
| 9 | 8 | Emergency alarm |
| Diagnostic connector | ||
| Watches | ||
| Front interior lighting lamp | ||
| Radio | ||
| Comfort system power relay (Kl. 86) | ||
| Mirror lighting lamps in sun visors | ||
| 10 | 25 | Heated rear window |
| 11 | 8 | 124 545: 0600, 1000, 1200, 1500: Carburetor electronics |
| 124 545: 1200, 1300, 1500, 2100: Transmission oil cooler | ||
| 124 545 2100: Intake manifold heater | ||
| 16 | 124 545 2500: Alarm | |
| 12 | 25 | 124 545: 0600, 0700, 1000, 1200, 2100: Heater motor |
| 16 | 124 545 2500: Alarm | |
| 13 | 8 | Left dipped beam |
| 14 | 8 | Right dipped beam |
| 15 | 8 | Left high beam |
| 16 | 124 545 2500: | |
| Left high beam | ||
| Additional high beam (left) | ||
| 16 | 8 | Right high beam |
| Headlight high beam indicator | ||
| 16 | 124 545 2500: | |
| Right high beam | ||
| Headlight high beam indicator | ||
| Additional high beam (right) | ||
| A | 16 | Luke |
| Orthopedic seat back (124 545: 0600, 0700, 0900, 1000, 1200, 1300) | ||
| Heated front seats (124 545: 0600, 0700, 0900, 1000, 1200, 1300) | ||
| Electric headrests (124 545: 0600, 1000, 1200) | ||
| 25 | 124 545 1500: Glass lifts | |
| 8 | 124 545 2700: Roof control unit | |
| B | 8 | Electric mirrors |
| Heated mirrors | ||
| Rear seat heating (rear heater) (124 545: 0600, 1000, 1200, 2100) | ||
| Seat belt feeder system (124 545: 1200, 1300, 1500, 1600, 2100, 2200, 2700) | ||
| Electric rear window blind (124 545: 1200, 1300, 1500, 1600, 2100, 2200, 2500) | ||
| C | 16 | Rear interior lighting lamp |
| Trunk lighting | ||
| Rear door lock | ||
| Central door locking system | ||
| Ceiling lights in doors | ||
| Automatic antenna | ||
| Electric seat adjustment motor with memory | ||
| Trailer turn signal control unit (124 545: 0600, 0700, 0900) | ||
| Seat belt feed system (124 545: 1200, 1300, 1500, 1600, 2100, 2200, 2700) | ||
| Lumbar support (124 545: 1200, 1300, 1500, 1600, 2100, 2200, 2700) | ||
| Reading lamp in the rear of the cabin (124 545: 0600, 1200, 1300, 1500, 1600, 2100, 2200, 2500) | ||
| CD changer | ||
| Amplifier | ||
| D | 16 | Additional fan |
| AND | 25 | Adjusting the position of the front seats |
| Adjustable steering column (memory) (except 124 545: 0700, 0900) | ||
| F | 25 | Adjusting the position of the front seats |
| Adjustable steering column (except 124 545: 0700, 0900, 2500) | ||
| G | 16 | 124 545: 0600, 0700, 0900, 1000: Window regulators (front left, rear right) |
| 124 545: 1200, 1300: Window regulators (front left, rear right) | ||
| 25 | 124 545: 1500, 1600, 2100, 2200, 2500, 2700: Window regulators (front left, front right) | |
| H | 16 | 124 545: 0600, 0700, 0900, 1000: Window regulators (front right, rear left) |
| 25 | 124 545: 1200, 1300: Window regulators (front right, rear left) | |
| 124 545: 1500, 1600, 2100, 2200, 2500, 2700: Window regulators (rear left, rear right) | ||
| Relay | ||
| A | Power window actuator, sunroof, power seat relay | |
| Electric seats | ||
| B | Air conditioner condenser fan | |
| C | Air conditioner condenser fan | |
| D | Headlight cleaner | |
| AND | Fuse connector | |
| Oxygen sensor relay | ||
| F | Seat heating relay | |
| Electric windows | ||
| Comfort system power relay (since 1990) | ||
| G | Seat belt warning | |
| Fuel return valve relay | ||
| H | Combined relay: turn signals, hazard warning lights, rear window heater, wiper motor, anti-theft system | |
| I | Power seat diode (since 1990) | |
| Power window actuator diode | ||
| Parking brake /ASR/ electronic accelerator pedal (from 1992, 400E/ 500E) | ||
| K | Lamp health check system unit | |
The fuse block diagram number, which is located on the cover, is indicated in brackets. (example: 124 545 2200)
Fuse number 1 is responsible for the cigarette lighter.
Relay block
An additional relay unit can be installed under the hood on the right side.
| № | Description |
|---|---|
| 1 | Fuel pump relay |
| 2 | Surge protection relay for electronic components of injection and ABS systems |
| 3 | Air conditioner compressor control unit |
Additional elements
Fuel pump relay (K27)
| № | Marking |
|---|---|
| 11 | except 124.034, 124.036 |
| 12 | under the rear seat (models; 124.034 (E420), 124.036 (E500)) |
| N6 | Air conditioner compressor control unit |
| N30 | ABS control unit |
Starter lockout relay (K38)
Other elements
| № | Marking |
|---|---|
| K11/1 | Left headrest relay |
| K11/2 | Right headrest relay |
| K12/1 | Intermittent rear wiper timer |
| N13 | Engine overload protection relay/cruise control |
| N14 | Spark plug relay |
| N28 | Trailer control unit |