Scania 4 series is a truck tractor produced with 2-, 3- or 4-axle variants with different power units in 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 and 2005. In this publication you will find a description of the fuses and relays of the 4th generation Scania with block diagrams and their locations. We will highlight the fuse responsible for the cigarette lighter.

The purpose of the fuses and relays in your Scania 4 series may differ from the one shown and depends on the year of manufacture and the level of equipment. Check the purpose with your diagram on the back of the protective cover or other technical documentation.
Fuse and relay box
The main block with fuses and relays is located in the instrument panel, on the passenger side behind the protective cover.

It consists of two parts. The left one contains fuses and relays for the main equipment (lighting, suspension, engine control, ABS, etc.). The right one contains fuses that are mainly connected to additional equipment (power take-off, independent heater, navigation, etc.)
Scheme

Description of fuses
- Odometer, tachograph, buzzer, ABS diagnostics 10A
- Flashing lights, speed limiter, axle load limiter 10A
- Reverse signals 20A
- Engine brake, white smoke limiter 10A
- Gearbox 10A
- ABS, brake lights 20A
- Axle lift, differential lock, power take-off, 10A pressure sensor
- Windscreen wipers, windscreen washers 20A
- Horn, Fan, Air Conditioner, Temperature Module 20A
- Air suspension, steering axles, retarder 10A
- Window lifter left side 20A
- Window lifter right side, fog lights 20A
- Trailer ABS 30A
- Tachograph, mileage counter, seat 10A
- Interior lighting, central locking, 20A cigarette lighter
- Diagnostics, local lighting 20A
- Radio equipment, seat 20A
- ABS valve relay 20A
- Power supply of the engine control unit 20A
- EDC Engine Control Unit, Fuel Cutoff 10A
- EBS 30A
- Heated seats and rear view mirrors 20A
- ABS control unit, trailer 5A
- Headlight adjustment, air dryer 20A
- Instrument panel lighting 10A
- Work lighting, roof lighting 20A
- Left side light, upper side lights 20A
- Right side light 20A
- Front and rear fog lights 20A
- Left high beam 10A
- Right high beam, local lighting 10A
- Left low beam 10A
- Right low beam, headlight height adjustment 10A
- Additional heater, cabin tilt 20A
- Heater, temperature control unit, refrigerator 10A
- Flame start, power take-off, cigarette lighter , alarm 10A
- Fuel heater 20A
- Flame start, fuel heater, seat heater 10A
- Battery heater, automatic chassis lubrication 10A
- Electric sunroof, FMS trip computer, 20A cellular connection
- Opticruise, block clock, alarm 10A
- EBS 20A
- Additional equipment 20A
- Filter heating, additional equipment 20A
- Additional equipment 10A
Fuse number 15 for 20A is responsible for the operation of the cigarette lighter.
Purpose of the relay
| RP1 | Power supply (bus 15, power supply for fuses 1-13, 18,21,23) |
| RP2 | Power supply (bus 15, power supply for fuses 36,37) |
| RP3 | High and low beam headlights |
| RP4 | Power supply bus 61 (consumers with the engine running) |
| RP5 | Power supply bus 58 (parking lights, backlight) |
| RP6 | Windscreen wipers, intermittent mode |
| RP7 | Brake lights |
| RP8 | Additional lights |
| RP9 | Electronic Engine Control (EDC) Power Supply |
| RP10 | Buzzer |
| RP11 | Reversing lights |
| RP12 | Front fog lights |
| RP13 | Rear fog lights |
| RP14 | EDC diode block |
| RP15 | Gearbox row shift control |
| RP16 | ABS trailer |
| RP17 | Reducing the braking force for the additional axle |
| RP18 | Depending on the version |
| RP19 | Interior heater fan |
| RP20 | Interior heater fan |
| RP21 | Additional lights |
| RP22 | Engine brake (depending on version) |
| RP23 | White smoke limiter, starter lock (depending on version) |
| RP24 | Air conditioner |
| RP25 | Air conditioner |
| RP26 | Additional heater |
| RP27 | Additional heater |
| RP28 | Additional heater |
| RP29 | Differential lock, 6-channel ABS (diagonal 1) |
| RP30 | Depending on the version, 6-channel ABS (diagonal 2) |
| RP31 | Depending on the version, 6-channel ABS diagnostic lamp |
| RP32 | Power take-off |
| RP33 | Fuel heater |
| RP34 | Reserve |