Audi 90 (B3; 1987 – 1991) – fuse and relay box diagram
Year of production: 1987, 1988, 1989, 1990, 1991
This article covers the Audi 90 (B3), produced from 1987 to 1991. It includes fuse box diagrams for the 1987, 1988, 1989, 1990 and 1991 models, provides details on the location of the fuse panels inside the vehicle, and explains the function and layout of each fuse.
Fuse box diagram
Assignment of the fuses in the fuse box
| No. |
Description |
A |
| 1 | Fog lights, rear fog light | 15 |
| 2 | Emergency flashers | 15 |
| 3 | Horn, brake lights | 25 |
| 4 | Reading lights, luggage compartment, cigar lighter, interior lights, make-up mirror, Board Computer, radio, clock, auto climate control, alarm system | 15 |
| 5 | Radiator cooling fan | 30 |
| 6 | Side marker, park lights, right | 5 |
| 7 | Side marker, park lights, left | 5 |
| 8 | Hi-beam headlight, right, hi-beam indicator light | 10 |
| 9 | Hi-beam headlight, left | 10 |
| 10 | Low beam headlight, right | 10 |
| 11 | Low beam headlight, left | 10 |
| 12 | Instrument cluster, back-up lights, Auto-Check, cruise control, ABS, Board Computer, differential locks, electronic thermoswitch, throttle valve time control unit, radiator cooling fan after-run control unit | 15 |
| 13 | Fuel pump, warm-up regulator | 15 |
| 14 | Glove compartment, engine compartment, license plate lights | 5 |
| 15 | Windshield wipers, thermoswitch, radiator cooling fan, turn signals, A/C pressure switch | 25 |
| 16 | Rear window heat element, outside mirror heat element | 30 |
| 17 | Fresh air blower, A/C | 30 |
| 18 | Power mirrors, rear window wiper (Coupe) | 5 |
| 19 | Central locking system, heated lock system | 10 |
| 20 | Radiator cooling fan (step 1), radiator cool fan after-run | 30 |
| 21 | Diagnostic | 10 |
| 21 | Rear cigar lighter | 25 |
| 22 | Not used | – |
| 23 | Power seats with memory, power seat control unit | 30 |
| 24 | Engine control I | 10 |
| 25 | Heated seats | 30 |
| 26 | Daytime driving lights (Canada) | 5 |
| 27 | Engine control I (from September, 1987) | 10 |
| 28 | Engine control II | 15 |
| 29 | Spare fuses | 15 |
| Relay | ||
| I | Fog lights, J5 | |
| II | up to 1990: Radiator cooling tan (stage 2), J101 from 1990: Not used |
|
| III | Radiator cooling fan after-run control unit, J138 | |
| IV | up to 1990: Not used from 1990: Headlight washer system, J39 |
|
| V | Load reduction relay, J18 | |
| VI | up to 1990: A/C fresh air blower, J11 from 1990: Radiator cooling fan high speed relay, J101 |
|
| VII | Horn, J4 | |
| VIII | Bridge between contact 36 and 38 for manual transmissions Auto transmission, J60 |
|
| IX | Intermittent washer/wiper, J31 | |
| X | Fuel pump, J17 | |
| XI | Radiator cooling fan (stage 1), J26 | |
Auxiliary relay panel
Assignment of the fuses in the auxiliary relay panel
| No. | Description |
| 1 | ABS system, J156 |
| 2 | Seat belt, radio, parking light warning, J152 |
| 3 | Interior light control unit, J140 |
| 4 | A/C clutch control unit, J153 |
| 5 | Not used |
| 6 | Dynamic oil pressure warning (without Auto-Check), J114 Lamp control unit, front (with Auto-Check), J123 |
| 7 | Not used |
| 8 | Not used |
| 9 | Not used |
| 10 | Not used |
| 11 | Not used |
| 12 | Circuit breaker (power seats with memory, power windows, power sunroof), S43 |
| 13 | Seat heater control unit, passenger. J132 |
| 14 | Seat heater control unit, driver, J131 |
| 15 | Sunroof relay, J139 Sunroof and power window control unit, J139 |
| 16 | Sunroof and power window control unit, J139 |
| 17 | Wire distributor adaptor, (optional equipment connector) |
| 18 | Not used |
WARNING: Terminal and harness assignments for individual connectors will vary depending on vehicle equipment level, model, and market.