If you drive a 2003–2006 Smart Roadster, understanding your fuse box layout can save you time, stress, and unexpected repair costs.
This guide provides a clear fuse box diagram, helping you identify the correct fuses for lights, accessories, engine components, and more.
Whether you’re fixing an electrical issue or replacing a blown fuse, this breakdown makes troubleshooting quick and easy.
Table of Contents
Cigar lighter (power outlet) fuse in the Smart Roadster is the fuse #21 in the Instrument panel fuse box.
Passenger Compartment
| Fuse Number | Description | Fuse Amp |
|---|---|---|
| 1 | Starter | 25 |
| 2 | Windscreen wipers, washer pump | 20 |
| 3 | Heater blower, seat heater | 20 |
| 4 | Power windows | 30 |
| 5 | Light switch | 7.5 |
| 6 | Parking lights/tail lights, right | 7.5 |
| 7 | Parking lights/tail lights, left | 7.5 |
| 8 | Terminal 87/3 master relay (engine) | 20 |
| 9 | Terminal 87/2 master relay (engine) | 10 |
| 10 | Terminal 87/1 master relay (engine) | 15 |
| 11 | Instrument cluster, safety cluster, OBD, Horn (only with leather sport steering wheel with steering wheel rocker switch system) | 7.5 |
| 12 | Radio CD, interior light | 15 |
| 13 | Fog lamps | 15 |
| 14 | ESP valves | 25 |
| 15 | Charge air cooler, Air conditioning compressor | 15 |
| 16 | Electric fuel pump | 10 |
| 17 | Rear window wiper | 15 |
| 18 | Airbag triggering device, ESP | 7.5 |
| 19 | Mirror adjustment | 7.5 |
| 20 | Radio, CD, instrument cluster, tachometer, OBD, backup lamp, CD changer | 15 |
| 21 | Power socket, Cigarette lighter | 15 |
| 22 | Low beam light, right | 7.5 |
| 23 | Low beam light, left | 7.5 |
| 24 | High beam light, right | 7.5 |
| 25 | High beam light, left/combined light | 7.5 |
| 26 | Brake light | 15 |
| 27 | Engine control unit | 7.5 |
| 28 | Rear window heater/engine fan | 30 |
| 29 | Soft top | 30 |
| 30 | Manual gearbox | 40 |
| 31 | Horn, central locking, rear lid remote unlocking | 30 |
| 32 | Secondary air injection pump (emission control) | 30 |
| 33 | Ignition switch | 50 |
| 34 | ESP control unit | 50 |
| 35 | Steering assist control unit | 30 |
| 36 | Backup fuse 15 | – |
| 37 | Backup fuse 15 (W450, glass sliding roof) | 15 |
| 38 | Backup fuse 15 | – |
| 39 | Backup fuse 15 | – |
| 40 | Backup fuse 30 | – |
| 41 | Backup fuse 30 | – |
| 42 | Backup fuse 30 | – |
| 43 | Backup fuse 30 | 25 |
| 44 | Backup fuse 30, seat heater | 25 |
| Relays | ||
| A | Wiper system relay | |
| B | Fog lamp relay | |
| C | Left heated seat control unit | |
| D | Right heated seat control unit |
Also Read: How to read a car fuse box diagram? 5 Easy Steps
Frequently Asked Questions (FAQs)
My 12V power socket (cigarette lighter) is not working. Which fuse should I check?
This is a very frequent failure point due to high-power accessories.
Fuse Location: Check the main Driver’s Side Dashboard Fuse Box.
Fuse Type: Look for a fuse labeled “Cigar Lighter,” “12V Socket,” or “Accessory.” It is typically a 15 Amp (Light Blue) fuse.
The electric windows or the soft top are not operating. Which fuses should I check?
The main power for these systems is protected by fuses in the Driver’s Side Dashboard Fuse Box.
Electric Windows: Check the fuses related to the “Window Regulators” (often 20 Amp Yellow fuses).
Soft Top/Vario Roof: Check the dedicated fuse labeled “Roof” or “Soft Top Control” (fuse rating may vary, typically 15A to 25A).
My headlights or interior courtesy lights have failed. Where are the fuses located?
Headlights/Tail Lights: Check the fuses labeled “Main Beam,” “Dipped Beam,” or “Taillight” in the Driver’s Side Dashboard Fuse Box. These are usually 10 Amp (Red) fuses.
Interior Lights (Room/Courtesy): Check the fuse labeled “ROOM” or “Interior Lamp” (often 5 Amp or 10 Amp).
The windshield wipers or washer pump have stopped working. Is there a fuse for this?
Yes, the main power for the wiper motor is fused.
Wiper Motor: Check the main fuse labeled “Wiper Motor” in the Driver’s Side Dashboard Fuse Box. This is often a 30 Amp (Green) fuse.