Audi 100 C4 A6 Avant fuse and relay

Production of the Audi 100 C4 45 began at the end of 1990. This model was produced from 1991 to 1994. The model name was then changed to Audi A6, and production continued from 1995 to 1997. This material provides information on fuses and relays for the Audi 100 C4 and Audi A6 C4 from 1990 to 1997, including box diagrams and their locations.

Audi c4 a6

The purpose of fuses and relays may differ from those presented and may vary depending on the level of equipment, model and market of the vehicle.


general arrangement of blocks in the car C4

  1. Additional relay and fuse board No. 1;
  2. Fuse and relay box (Audi 100), fuse box (Audi A6);
  3. Connecting box No. 1;
  4. Central switchgear with relay box;
  5. Additional mounting box No. 2;
  6. Connecting box No. 2;
  7. Ignition system box;
  8. Additional mounting box No. 3;
  9. Connection box No. 3.

Changes in the schemes are possible depending on the equipment and the year of manufacture of your car. Be careful.

Additional box – No. 1

Located in the engine compartment. To access, remove the protective cover by sliding the latches.


For cars produced before 1994


Additional board for relay C4


1Not used
2Relay for seat belt control, parking light
3Time delay relay for indoor lighting
4Not used
5Headlight relay
6Not used
7Relay for switching on the 3rd fan speed
8ABS relay
9Not used
10Power window relay
11Power window relay
12Rear window washer and wiper relay
13Not used
14Power window overload relay
15Driver’s seat heater relay
16Passenger seat heater relay
17Not used

For cars produced from 1994


Additional relay board A6 C4


1Cooling fan control relay when the engine is not running
2Engine cooling fan relay
3Relay for switching on the 3rd fan speed
4Fog lamp relay
5Not used
6Relay for intensive glass washer system
7Daytime running light relay
8Gear selector lamp relay
9A / C clutch relay
10Relay for turning on the air conditioner module
11Rear window wiper and washer relay
12Not used
13Loudspeaker power relay
14Lamp health control unit
15Lamp health control unit
16Servotronic power steering control unit
17Air conditioner relay
Circuit breakers
A1Automatic closing of windows
A2central locking
A3Window lifters
A5Seat heating
B1Seat adjustment memory
B2Electric seat
B3Heated door lock cylinders
B4Not used

Main box – No. 2

For cars produced before 1994


relay and fuse box


115Rear Fog Lamp Bulbs
215Hazard warning system
325Horn, brake light
415Clock, cigarette lighter , climate control, interior and trunk lighting lamps, cruise control, radio tape recorder
5Not used
65Lamps for the right tail lamp, parking lamp and side marker lamp
75Lamps of the left tail lamp, parking lamp and side marker lamp
810Right headlight high beam lamp, headlight high beam indicator lamp
9Left headlight high beam lamp
1010Low beam lamp, right headlight
1110Low beam lamp, left headlight
1215Differential lock system, reversing lamp, cruise control, interior heating system
1315Fuel pump
145Lamps for license plate, instrument cluster, ashtray, climate control panel, engine compartment and glove box
1525Wiper motor, turn signal lamps, air conditioning, heated windshield washer jets, engine cooling fan temperature sensor
1630Heated rear window, heated mirrors
1730Climate control system (fan)
1815Rear wiper
1910Central door locking system, anti-theft system, door lock heater
2030Seat heater
2110Diagnostic unit
22Not used
235License plate light
24Not used
2530Driver’s seat adjustment motors, driver’s seat memory unit
265Instrument cluster, power mirrors, automatic check system, cruise control unit (if installed)
2710Ignition control unit
2815Fuel injection control unit
2910Heated oxygen sensor
30Not used
31Back-up fuses
1Not used
2Relay for switching on the 2nd fan speed
3Relay for switching on the 1st fan speed
4Not used
5Unloading relay
6Not used
7Horn relay
8Relay for control of automatic transmission and anti-theft system
9Not used
10Fuel pump relay
11Not used

For cars produced from 1994 

The fuses are situated on the left side of the dashboard, beneath a cover that is distinguishable from the surrounding area.

photo of fuse box


fuse numbers C4

Protected components

  1. 10A – Right high beam headlamp and high beam warning lamp
  2. 10A – Left high beam headlamp
  3. 10A – Right dipped beam headlamp
  4. 10A – Left dipped beam headlamp
  5. 5A – Right side light
  6. 5A – Left side marker fire
  7. 15A – License plate, glove compartment, engine compartment, temperature control panel, ashtray and dashboard lamps
  8. 15A – Clock, map reading lamps, trunk lighting lamp, lighter, interior lighting lamps, visor lamps, on-board computer , rear-view mirrors adjusters, programmable seat adjusters
  9. 10A – Stop lights
  10. 15A – Warning lamp
  11. 30A – Heater fan, air conditioner
  12. 30A – Heated rear window and rear-view mirrors
  13. 25A – Windshield wipers, direction indicators, cooling fan, sprinkler heaters, gearbox oil temperature sensor
  14. 15A – Reversing lights, glass washers, cruise control, differential lock, multifunction sensor, speedometer sensor, water filter, automatic transmission
  15. 5A – Instrument panel, rear-view mirrors, on-board computer
  16. 15A – Fog lights
  17. 20A – Fuel pump, heating valve
  18. 15A – Rear window wiper
  19. 25A – Diagnostic system, sound signal, fan relay
  20. 5A – Cruise control system, automatic transmission
  21. 15A – ABS

Central switchgear – No. 4

Further only for cars Audi A6 C4 from 1994 to 1997 release

 parsing and access to the relay board


1Unloading relay
2Horn relay
3Relay for headlight washer system
4Central locking
relay Tail light relay (manual transmission)
Automatic transmission relay (P / N)
5Relay for interruption of the wiper and washer
6Fuel pump relay

Additional mounting box – No. 5


Additional mounting block C4


1Power window control unit
2Power window control unit
3Electric control unit for rear-view mirrors
Automatic closing of windows
4Electric control unit for rear-view mirror
ABS combi
5Shift Lock Control Module
6Automatic transmission
7Cooling fan fuse
Electronic damping control module (fuse)
8Cooling fan (fuse)

Connecting box 3 – No. 9


connecting block 3Description

1Not used
2Airbag warning lamp relay
3Not used
4Not used
5Auxiliary air pump relay
6Not used
7Not used
8Exhaust manifold auxiliary air pump fuse

Check out our YouTube video for more on this topic. Don’t forget to subscribe!

You still have questions, ask them in the comments.

Leave a Reply

Your email address will not be published. Required fields are marked *