Audi A3 / S3 8L (1996-2003) – Fuse Box and Relay Diagrams

Audi A3 and S3 8L (1996-2003) use several separate fuse and relay carriers: the main 44-fuse dashboard panel, the engine plenum relay/fuse holder, central electronics beneath the driver’s footwell, supplementary Z13 relay plate and a battery-mounted high-current distribution block. The facelift from 2000 and engine, drivetrain and country-specific wiring can change the fitted relays and fuse ratings.

The article preserves all 99 rows from the seven Polish reference tables, including the 19-row fault-location index, the three-row generation comparison, relay sockets and unused positions. A separate eighth table adds eight manufacturer-style S131-S164 high-current code references, because the simplified battery diagram in the old source uses a different numerical index. These references must be checked against the labels fitted to the actual vehicle rather than assumed equivalent by their row number.

Where are the Audi A3 8L fuse boxes?

Main dashboard fuse panel: switch off the ignition, open the driver’s door and remove the plastic panel on the left end of the dashboard on most left-hand-drive models. The 44 numbered positions are behind the cover. Some equipment variants change the orientation of trim on right-hand-drive cars. Read the fuse-label card on the vehicle before removing a fuse.

Central relays R and Z13: remove the appropriate lower dashboard trim at the driver’s footwell to access the main relay carrier behind the left-side panel; a separate 13-position Z13 unit may be mounted above it. Reaching the carrier is different from pulling a normal dashboard fuse, and the rear wiring and clips should not be forced.

Under the bonnet: one smaller three-position relay/fuse holder sits in the plenum electrical box by the windscreen bulkhead. The large battery-fuse unit is mounted at the battery positive-terminal area. Disconnecting or replacing any high-current alternator, diesel heater, fan or ABS fusible link requires the manufacturer’s correct isolation procedure, not a normal blade-fuse puller.

Most frequently checked Audi A3 8L circuits

These are 19 cross-references to fuses or relays in the real carriers. They are not another physical 19-fuse box. The full cabin and engine allocation follows below.

Is this an 8L, 8P or 8V?

A vehicle registered in 2003 can be first-generation A3 8L or the beginning of the later A3 8P. The hatchback body and carrier layout, not the registration year alone, identify the correct diagram. The following three reference rows compare model generations rather than fuse positions.

Three-position plenum relay and fuse holder

This small unit in the engine-bay plenum supports secondary-air injection, engine electronics and selected brake-booster vacuum pump circuits. Manufacturer descriptions indicate the 20 A brake booster vacuum pump fuse at position 3 and the 40 A secondary air system fuse at position 4 can be omitted on later model-year vehicles. The relay positions are engine-specific and carry no blade-fuse amp rating.

Central relay plate R below the dashboard

Position I operates the horn, II unloads the X-contact, III handles the intermittent wipers, IV supplies the petrol fuel pump or diesel preheating according to engine, V is the diesel injection relay and VI controls fog lamps. The separate A and C supplementary fuses protect heated seats or power windows, while B is unoccupied in this version.

Supplementary thirteen-position relay plate Z13

The additional plate sits above the main relay carrier on cars with greater equipment. The original 13-position list includes both empty relay positions and relay functions for mirror folding, rear-light monitoring, telephone, starter lockout, headlamp washers and radiator fan after-run. The illustration shows the same central relay-board assembly, with Z13 identified as the upper section.

Main passenger compartment fuse box – positions 1-44

The main panel contains the cigarette lighter at fuse 41 (15 A), front wipers at 24 (20 A), rear wiper at 27 (10 A), fuel pump at 28 (15 A) for relevant petrol versions, horn 40 (20 A), heater blower 25 (25 A) and separate main/dipped headlights at 18-21 (10 A each).

Fuse 29 can be 15 A on petrol or 10 A on diesel engines, depending on installed management equipment. The older source chart has fuse 42 at 25 A for the radio; some equipment and model-year variants list alternative radio/navigation ratings. The source value is retained, but the car’s own fuse card must be used when replacing it.

Battery-mounted main high-current block – original simplified source list

The battery-mounted fuse bank contains the engine-control supply, glow plug power, cooling fan, interior distribution, alternator and ABS hydraulic pump circuits. The original simplified source list has seven rows, one of them a header-like entry labelled 1. Its numbered sequence does not exactly match manufacturer code lists. The seven legacy entries are preserved here for traceability, but are not a replacement for factory physical slot numbering.

Factory high-current identification – S131 to S164

Workshop references identify the major battery links using codes S131, S132, S133, S134 and S138 and the three auxiliary links S162-S164. The table below separates these factory codes from the old overview’s ambiguous indices. The current values shown for S131, S132, S133, S134, S138 and S162 are documented values for an applicable arrangement; S163/S164 ratings were not confirmed for every variant and are intentionally left unassigned. Before repair, compare the actual battery fuse plate and the manufacturer’s diagram for the VIN.

Electrical fault diagnosis – Audi A3 / S3 8L

12 V cigarette lighter dead: check side-dash fuse 41 (15 A), then inspect the socket for foreign metal or an accessory short. Front wipers stopped: check fuse 24 (20 A), relay III and motor/park-switch wiring; the rear wiper has fuse 27 (10 A).

Engine cranks but does not start: check the engine-specific fuse 28 (15 A) and relay IV on petrol cars. For diesels, the preheating and injection relays occupy different positions, and the battery-mounted glow-plug fusible link is relevant to cold starting. One headlamp fails: check individual fuses 18, 19, 20 and 21 (10 A each), plus the lamp holder and earth connection.

ABS warning: inspect the dash ABS fuse 9 (5 A), then the fitted battery high-current S162/S163 distribution and ABS module diagnostic codes. Several cabin consumers fail at once: inspect the battery positive distribution, main terminals and chassis grounds before replacing multiple small fuses.

Cabin blower not running: check 25 (25 A) and the fan control module. Heated rear screen fails: inspect 26 (20 A), rear-window relay, wiring and the heating strips in the glass. Remote locking and electric windows affected: compare the relevant 6, 14, 38, A and C circuits with the equipped vehicle, including the possibility of a wet control module.

Browse other Audi fuse box diagrams by model and generation. The 8L carrier cannot be replaced with A3 8P/8V or later Audi models simply because a fuse shares the same number.