The first-generation Audi A4 (B5 platform) was produced until 2001 with minor mid-cycle updates. Initially released strictly as a sedan, the station wagon (Avant) variant followed a year later. The vehicle was built on the same platform as the fifth-generation Volkswagen Passat (B5). In terms of overall dimensions, the A4 is virtually identical to the outgoing Audi 80. This guide provides a detailed breakdown of all fuse and relay diagrams for the Audi A4 B5 (model years 1994, 1995, 1996, 1997, 1998, 1999, 2000, and 2001, B5 platform).
Below you will find the locations, diagrams, and photos of all power distribution centers. Pay special attention to the fuses responsible for the fuel pump and cigarette lighter.
Passenger Compartment
Main Fuse Box
The main fuse panel is located behind the end panel on the driver's side of the dashboard.
General view.
| Fuse Diagram | ||
|---|---|---|
|
||
| No. | Rating (A) | Circuit / Protected Component |
| 1 | 5 | Heated windshield washer nozzles |
| 2 | 10 | Turn signals / direction indicators |
| 3 | 5 | Headlight washer relay, glove box illumination, engine compartment light, automatic climate control system, automatic transmission gear selector display, instrument cluster |
| 4 | 5 | License plate lights |
| 5 | 10 | Instrument cluster, heated seats, automatic transmission display, power mirror switch, airbag indicator light, outside temperature gauge, navigation system, parking lights |
| 6 | 5 | Central locking system |
| 7 | 10 | ABS system |
| 8 | 5 | Cellular telephone |
| 9 | 10 | Heated exterior mirrors and door lock cylinders |
| 10 | 5 | Headlight range control (leveling motor) |
| 11 | 5 | Cruise control (automatic transmission) |
| 12 | 10 | On-board diagnostics (OBD) system |
| 13 | 10 | Brake lights (stop lights) |
| 14 | 10 | Interior lighting, reading lights, anti-theft alarm system, vanity mirror light |
| 15 | 10 | Instrument cluster, 4-speed automatic transmission, climate control (A/C), navigation system |
| 16 | 5 | ABS system |
| 17 | 10 | Heated door lock cylinders |
| 18 | 10 | Right high-beam headlight |
| 19 | 10 | Left high-beam headlight |
| 20 | 15 | Right low-beam headlight, electric headlight leveling control |
| 21 | 15 | Left low-beam headlight, headlight range control |
| 22 | 5 | Right parking / side marker lights |
| 23 | 5 | Left parking / side marker lights |
| 24 | 25 | Windshield wipers, washer pump, intermittent wiper control relay |
| 25 | 30 | Blower motor (heater fan), air conditioning system |
| 26 | 30 | Heated rear window, heated side mirrors, air recirculation control |
| 27 | - | - |
| 28 | 15 | Engine management control unit (ECU) |
| 30 | 20 | Power sunroof |
| 31 | 15 | Reverse lights, cruise control, automatic transmission, diagnostic connector (OBD) |
| 32 | 20 | Engine management control unit (ECU) |
| 33 | 15 | Cigarette lighter fuse |
| 34 | 15 | Engine management control unit (ECU) |
| 35 | 30 | Trailer towing connector / socket |
| 36 | 15 | Telephone, audio head unit (radio) |
| 38 | 15 | Luggage compartment light, central locking system |
| 39 | 15 | Hazard warning lights |
| 40 | 25 | Horn |
| 41 | 25 | ABS system (hydraulic modulator/pump) |
| 42 | 40 | Radiator cooling fan |
| 43 | 5 | S-contact / ignition switch terminal S (central locking, radio, navigation system) |
| 44 | 30 | Heated seats |
Auxiliary Fuse Box
Diagram.
|
||
| No. | Description | Rating (A) |
| 18 | ABS hydraulic pump | 50 |
| 19 | Electric radiator fan | 40 |
| 21 | Radiator fan relay coil | 5 |
| 22 | Rear power windows | 30 |
| 23 | Front power windows | 30 |
| 24 | Central locking and anti-theft alarm system | 15 |
Relay Panel
The relay modules are located on the central electrical carrier underneath the dashboard on the driver's side.
| Diagram | |
|---|---|
|
|
| No. | Description |
| 1 | X-contact load reduction relay |
| 2 | Horn relay |
| 3 | Headlight washer system relay |
| 4 | Automatic transmission relay (starter interlock and reverse lights) or manual transmission bridge circuit |
| 5 | Intermittent wiper and washer control relay |
| 6 | Fuel pump relay or glow plug relay |
| Auxiliary Relay Carrier - Panel A | |
| 3 | A/C compressor clutch relay |
| 4 | Alarm system control module |
| 5 | |
| 7 | - |
| 8 | Daytime running light (DRL) relay |
| 9 | Headlight relay |
| 10 | Fog light relay |
| 11 | Power folding mirror control module |
| 12 | |
| 13 | - |
| 14 | Special signal system fuse (Taxi application) |
| 15 | - |
| 16 | Special signal system fuse (Taxi application) |
| 17 | Taximeter fuse (Taxi application) |
| 18 | ABS hydraulic pump fuse Two-way radio / transmitter fuse (Taxi application) |
Engine Compartment
An auxiliary relay box is located under the hood in the plenum chamber.
| Diagram | |
|---|---|
|
|
| No. | Description |
| 1 | Heated oxygen sensor (O2S) relay Coolant glow plug relay I |
| 2 | Coolant glow plug relay II |
| 3 | Direct diesel injection (TDI) control relay |
| 4-5 | - |
| 6 | Engine management / electronics fuse |
| 7 | Coolant glow plug fuse I |
| 8 | Coolant glow plug fuse II |
| 9 | Engine glow plug fuse |
| Auxiliary Relay Board | |
| 1 | Rear fog light relay |
| 2 | High-speed radiator fan relay (Lüfter voll auf) |
| 3 | Low-speed radiator fan relay (Stage 1) |
| 4 | Power window control module relay |
| 5-15 | - |
| 16 | Power seat adjustment fuse |
| 17 | - |
| 18 | ABS hydraulic pump fuse |
| 19 | Radiator fan fuse |
| 20 | - |
| 21 | Radiator fan speed changeover relay |
| 22 | Rear power window relay |
| 23 | Front power window relay |
| 24 | Central locking and anti-theft system relay |
