The Mercedes-Benz Actros features several fuse and relay boxes that protect the truck’s electrical systems. Depending on the model year and generation, fuse box locations and assignments may vary.
This guide helps locate fuse boxes and identify the most common fuses and relays found in Mercedes-Benz Actros trucks.
Mercedes-Benz Actros Fuse Box Locations
Most Actros models have multiple fuse and relay panels.
Main Fuse Box
Location:
- Passenger side dashboard
- Behind removable cover
- Accessible from inside the cab
Protected systems:
- Exterior lighting
- Wipers
- Horn
- Instrument cluster
- Climate control
Chassis Fuse Box
Location:
- Left side of chassis frame
- Near battery box
Protected systems:
- Trailer electrical circuits
- Air suspension
- Lift axle systems
- Auxiliary equipment
Battery Fuse Box
Location:
- Near battery compartment
Protected systems:
- Starter motor
- Alternator
- Main power distribution
- Engine control unit
Engine Compartment Fuse Box
Location:
- Engine bay
- Near ECU housing
Protected systems:
- Engine management
- AdBlue system
- Cooling fans
- Sensors
Dashboard Fuse Box Diagram
Typical dashboard fuse assignments:
| Fuse | Amperage | Function |
|---|---|---|
| F1 | 5A | Instrument Cluster |
| F2 | 10A | Interior Lighting |
| F3 | 15A | Radio System |
| F4 | 20A | Windshield Wipers |
| F5 | 15A | Horn |
| F6 | 10A | Diagnostic Connector |
| F7 | 20A | Auxiliary Socket |
| F8 | 15A | Climate Control |
| F9 | 10A | Central Locking |
| F10 | 20A | Power Windows |
Engine Fuse Box Diagram
Common engine compartment fuses:
| Fuse | Amperage | Protected Circuit |
|---|---|---|
| F21 | 15A | Engine ECU |
| F22 | 20A | Fuel Pump |
| F23 | 30A | Cooling Fan |
| F24 | 15A | AdBlue Pump |
| F25 | 10A | NOx Sensors |
| F26 | 15A | Turbo Control |
| F27 | 20A | Engine Sensors |
| F28 | 30A | Auxiliary Heater |
Common Relay Locations
Starter Relay
Controls:
- Starter motor activation
Symptoms of failure:
- No crank
- Intermittent starting
Fuel Pump Relay
Controls:
- Fuel delivery system
Symptoms:
- Engine won’t start
- Sudden engine shutdown
Cooling Fan Relay
Controls:
- Radiator cooling fan
Symptoms:
- Engine overheating
- Fan not operating
AdBlue Relay
Controls:
- SCR dosing system
- AdBlue pump
Symptoms:
- SCR warning
- AdBlue faults
Headlight Relay
Controls:
- Low beam
- High beam
Symptoms:
- Lighting failure
Most Frequently Blown Actros Fuses
Common fuse failures involve:
Cigarette Lighter Fuse
Symptoms:
- No power at 24V socket
Trailer Socket Fuse
Symptoms:
- Trailer lights not working
Wiper Fuse
Symptoms:
- Windshield wipers stop operating
Air Suspension Fuse
Symptoms:
- Suspension warning light
AdBlue Fuse
Symptoms:
- SCR malfunction warning
How to Replace a Fuse
- Turn ignition OFF.
- Locate the correct fuse panel.
- Identify the faulty fuse.
- Remove using fuse puller.
- Install a fuse with identical amperage.
- Test the circuit.
Never install a higher-rated fuse.
Common Electrical Problems
Battery Drain
Possible causes:
- Faulty relay
- Auxiliary equipment
- Wiring short circuit
Multiple Warning Lights
Possible causes:
- Ground connection issue
- Low battery voltage
- CAN bus communication fault
Fuse Repeatedly Blowing
Possible causes:
- Damaged wiring
- Short circuit
- Defective component
Fuse Box by Actros Generation
Actros MP1 (1996–2002)
Main locations:
- Dashboard
- Battery compartment
Actros MP2 (2003–2008)
Additional fuse modules:
- Chassis control systems
- Trailer management
Actros MP3 (2008–2011)
Expanded electrical architecture:
- SCR system protection
- Electronic braking system
Actros MP4 (2011–2018)
Additional modules:
- AdBlue control
- Advanced driver assistance systems
Actros MP5 (2018–Present)
Additional protection for:
- Multimedia Cockpit
- Radar systems
- Lane Assist
- Active Brake Assist
Frequently Asked Questions
Where is the fuse box on a Mercedes-Benz Actros?
Most models have fuse panels behind the dashboard cover, near the battery compartment, inside the engine bay, and on the chassis.
Which fuse controls the AdBlue system?
Typically dedicated SCR/AdBlue fuses are located in the engine compartment fuse box.
Why does a fuse keep blowing?
The most common causes are short circuits, damaged wiring, or defective electrical components.
Can I replace a fuse with a larger one?
No. Always use the exact amperage specified by Mercedes-Benz.
Conclusion
Mercedes-Benz Actros trucks use several fuse and relay panels to protect critical electrical systems. Knowing the fuse box locations, fuse assignments, and relay functions can help quickly diagnose electrical faults, reduce downtime, and simplify repairs.