Jaguar XJ8 (X308) 2003 Fuse Box Diagrams

The Jaguar XJ8 (X308) is a full-size luxury sedan built from 1997 to 2003 — the first XJ with the AJ-V8 engine (3.2 and 4.0 V8, supercharged in the XJR). It carries five fuse boxes: two in the engine compartment, one behind each rear heelboard and one in the luggage compartment.

Production: 1997–2003 · Platform: X308 · Model year: 2003

Not sure which model year your car is? Decode your VIN — the result links straight to the right fuse boxes.

Fuse and relay locations

Engine Compartment Fuse Box (Left-hand Side) — Engine compartment, left-hand side (box A)
Engine Compartment Relays (Outside the Fuse Box) — Engine compartment, outside the fuse boxes — see each relay
Engine Management Fuse Box — Engine compartment (box B)
Luggage Compartment Fuse Box (Electrical Carrier) — Luggage compartment, electrical carrier
Control Modules Compartment Relays — Engine compartment, passenger side
Front Seat Relays — Beneath the front seats
High Power Protection Module — Trunk, adjacent to the battery
Left-hand Heelboard Relays — Left-hand heelboard, beside the fuse box
Rear Compartment Fuse Box (Left-hand Heelboard) — Behind left-hand heelboard trim (box D)
Rear Compartment Fuse Box (Right-hand Heelboard) — Behind right-hand heelboard trim (box C)
Right-hand Heelboard Relays — Right-hand heelboard, at the fuse box

Engine Compartment Fuse Box (Left-hand Side)

Engine compartment, left-hand side (box A)

Factory name: Engine Compartment Fuse Box — LH sideAlso called: engine bay fuse box, under the bonnet fuse box, under the hood fuse box

The box outline on this diagram is drawn from photographs of the actual fuse box; ratings and circuit descriptions are verified against the fuse table for this model year.

Fuse list — Engine Compartment Fuse Box (Left-hand Side)

Fuse	Rating	Circuit
F1	10 A	Transmission control module.
F2	5 A	Screen heaters relay, alternator regulator.
F3	10 A	Security sounder, headlamp levelling, ignition coils +Ve, fog lamp switches.
F4	5 A	ABS control module.
F5	10 A	Adaptive damping, starter relay coil, engine management control module and relays.
F6	10 A	Right-hand dipped beam headlamp.
F7	30 A	Powerwash pump.
F8	10 A	Left-hand dipped beam headlamp.
F9	10 A	Security sounder.
F10	5 A	Rain Sensing.
F11	10 A	Right-hand horn. A
F12	30 A	Radiator cooling fans series/right-hand fast.
F13	10 A	Left-hand horn.
F14	30 A	Cooling fans left-hand fast.
F15	10 A	Air conditioning coolant pump.
F16	30 A	ABS pump control.
F17	15 A	Front fog lamps.
F18	30 A	ABS pump motor.
F19	10 A	Right-hand main beam headlamp.
F20	—	Not used
F21	10 A	Left-hand main beam headlamp.
F22	30 A	Wiper motor.

Relay	Function	Identification
R1	Air conditioning water pump	Brown case
R2	Front fog lamps	Brown case
R3	Main beam headlamps	Brown case
R4	Power wash pump (where fitted)	Brown case
R5	Dipped beam headlamps	Brown case
R6	Horns	Brown case
R7	Ignition +	Brown case

Engine Compartment Relays (Outside the Fuse Box)

Engine compartment, outside the fuse boxes — see each relay

Factory name: Engine Compartment RelaysAlso called: engine bay fuse box, under the bonnet fuse box, under the hood fuse box, relay box, relay panel, starter relay, screen heater relay

Relays — Engine Compartment Relays (Outside the Fuse Box)

Relay	Function	Identification
Front screen heater — left-hand side (where fitted)	Engine compartment, centrally at the bulkhead	Black case
Front screen heater — right-hand side (where fitted)	Engine compartment, centrally at the bulkhead	Black case
Radiator fan control module	Engine compartment, left-hand side, below the brake modulator under the spoiler	Black case
Wiper fast/slow	Engine compartment, left-hand side behind the radiator	Black case
Wiper on/off	Engine compartment, left-hand side behind the radiator	Black case

Engine Management Fuse Box

Engine compartment (box B)

Factory name: Engine Management Fuse BoxAlso called: engine management fuse box, ECM fuse box, engine bay fuse box, under the bonnet fuse box, under the hood fuse box

The box outline on this diagram is drawn from photographs of the actual fuse box; ratings and circuit descriptions are verified against the fuse table for this model year.

Fuse list — Engine Management Fuse Box

Fuse	Rating	Circuit
F1	20 A	Adaptive damping.
F2	15 A	Intercooler water pump (Supercharger).
F3	25 A	Starter solenoid.
F4	5 A	Engine control module.
F5	10 A	Fuel injectors.
F6	5 A	Transmission control module.
F7	—	Not used
F8	10 A	Air conditioning compressor clutch.
F9	30 A	Throttle motor.
F10	5 A	Engine control module, Park/Neutral switch, cruise control VSV 1 and 2 (where fitted), EGR valves. B
F11	30 A	HO2 sensor heaters.
F12	10 A	Air flowmeter, VVT solenoids.
F13	—	Not used
F14	10 A	HO2 sensor heaters relay (where fitted), EVAP valve, ignition coils relay, throttle motor relay, AC compressor clutch relay, radiator fans control module, CCV.
F15	30 A	Windscreen left-hand heater.
F16	5 A	Control module compartment cooling fan.
F17	30 A	Windscreen right-hand heater.
F18	10 A	Ignition coils, ignition amplifier.

Relay	Identification
Engine management system control relay	Brown case

Luggage Compartment Fuse Box (Electrical Carrier)

Luggage compartment, electrical carrier

Factory name: Luggage Compartment Fuse BoxAlso called: trunk fuse box, boot fuse box

The box outline on this diagram is drawn from photographs of the actual fuse box; ratings and circuit descriptions are verified against the fuse table for this model year.

Fuse list — Luggage Compartment Fuse Box (Electrical Carrier)

Fuse	Rating	Circuit
F1	10 A	Security and locking control module (Reversing lamps, rear fog lamps, stop lamps, electrochromic mirror).
F2	5 A	Fuel filler flap.
F3	5 A	Audio system.
F4	5 A	Radio telephone, ‘E’ post lamps, navigation.
F5	25 A	Cigar lighters.
F6	—	Not used
F7	20 A	Fuel pump.
F8	10 A	High mounted stop lamp, caravan/trailer stop lamps.
F9	10 A	Antenna motor.
F10	10 A	Security and locking control module (luggage compartment release, caravan/trailer direction indicators, fuel filler flap relay). E
F11	10 A	Accessory sockets.
F12	30 A	Audio system power amplifier.
F13	—	Not used
F14	5 A	Navigation.
F15	20 A	Fuel pump (supercharger, where fitted).
F16	20 A	Caravan/trailer connector.
F17	25 A	Heated rear screen.
F18	20 A	Rear seat movement.
F19	5 A	Right-hand side lamps, left-hand and right-hand number plate lights, caravan/ trailer.
F20	20 A	Rear seat movement.
F21	5 A	Left-hand side lamps, left-hand and right-hand sidemarker lights, caravan/trailer.
F22	5 A	Audio / telephone.

Relay	Function	Identification
R1	Fuel pump — supercharged only	Brown case
R2	Heated rear window	Brown case
R3	Tail and number plate lamps	Brown case
R4	Fuel pump	Brown case
R5	Stop lamps	Brown case
R6	Accessory socket (where fitted)	Brown case
R7	Auxiliary +	Brown case

Control Modules Compartment Relays

Engine compartment, passenger side

Factory name: Engine and Transmission Control Modules Compartment — relaysAlso called: engine bay fuse box, under the bonnet fuse box, under the hood fuse box, relay box, relay panel, engine management fuse box, ECM fuse box, ignition coil relay

Relays — Control Modules Compartment Relays

Relay	Function	Identification
R1	Intercooler water pump (where fitted) — micro-relay	Black case
R2	Air conditioning compressor clutch	Brown case
R3	Ignition coil	Brown case
R4	Throttle motor	Brown case
R5	Starter solenoid	Brown case
R6	HO2 sensor heaters	Brown case
R7	Fuel injection — micro-relay	Black case

Front Seat Relays

Beneath the front seats

Factory name: Front Seat RelaysAlso called: relay box, relay panel, seat relay, seat heater relay

Relays — Front Seat Relays

Relay
Seat heater relay
Seat lower relay (LHD)
Seat lower relay (RHD)
Seat raise relay (LHD)
Seat raise relay (RHD)

High Power Protection Module

Trunk, adjacent to the battery

Factory name: High Power Protection ModuleAlso called: megafuse, battery fuse box, battery junction box, starter fuse, main fusible link, trunk fuse box, boot fuse box

Fuse list — High Power Protection Module

Fuse	Rating	Circuit
POWER BUS SUPPLY	250 A	Battery to the vehicle power buses, connectors BT62 and BT63
STARTER SUPPLY	500 A	Battery to the starter motor, connector BT61

Left-hand Heelboard Relays

Left-hand heelboard, beside the fuse box

Factory name: Left-hand Heelboard RelaysAlso called: relay box, relay panel, heelboard relays, door locking relay

Relays — Left-hand Heelboard Relays

Relay
A/C isolate relay
Door locking relay
Ignition positive relay
Mirror fold-back relay
Mirror fold-out relay

Rear Compartment Fuse Box (Left-hand Heelboard)

Behind left-hand heelboard trim (box D)

Factory name: Rear Compartment Fuse Box — LH heelboardAlso called: under rear seat fuse box, rear fuse box

The box outline on this diagram is drawn from photographs of the actual fuse box; ratings and circuit descriptions are verified against the fuse table for this model year.

Fuse list — Rear Compartment Fuse Box (Left-hand Heelboard)

Fuse	Rating	Circuit
F1	20 A	Right-hand seat control module.
F2	5 A	Rear window switchpack, driver door key barrel, driver door switchpack and memory.
F3	5 A	Dimmer module.
F4	5 A	Diagnostic connector.
F5	15 A	Body processor module.
F6	5 A	Centre console switchpack (includes clock), reader exciter ECM.
F7	15 A	Body processor module (battery supply for solenoids, lamps and motors).
F8	5 A	Steering column adjust switch, driver seat switchpack.
F9	10 A	Radio/cassette head unit.
F10	5 A	Airbag/SRS.
F11	20 A	Air conditioning left-hand blower motor. D
F12	10 A	Door mirror heaters relay, air conditioning, blower motor relays, power steering control module.
F13	25 A	Left-hand rear window.
F14	10 A	Cruise control switch, instrument cluster, catalytic converter over temperature warning.
F15	25 A	Left-hand door control module.
F16	5 A	Electrochromic interior mirror (where fitted), centre console switchpack, gear selector, traction control switch illumination, J-gate mode switch illumination. Pin A9 luggage relay, fuel pump relay, secondary fuel pump relay (supercharged). Pin A5: feed to fuses 10
F17	10 A	Accessory supply.
F18	5 A	Instrument cluster.

Rear Compartment Fuse Box (Right-hand Heelboard)

Behind right-hand heelboard trim (box C)

Factory name: Rear Compartment Fuse Box — RH heelboardAlso called: under rear seat fuse box, rear fuse box

The box outline on this diagram is drawn from photographs of the actual fuse box; ratings and circuit descriptions are verified against the fuse table for this model year.

Fuse list — Rear Compartment Fuse Box (Right-hand Heelboard)

Fuse	Rating	Circuit
F1	20 A	Left-hand seat control module.
F2	15 A	Door lock relay, door locking actuators.
F3	15 A	Body processor module.
F4	10 A	Door mirror heaters, mirror foldback.
F5	5 A	Passenger seat switchpack.
F6	10 A	Air conditioning.
F7	20 A	Body processor module (column motor power).
F8	5 A	Rear window switchpack, passenger door switchpack.
F9	20 A	Rear seat heaters.
F10	5 A	Jaguar Diagnostic System. C
F11	20 A	Air conditioning right-hand blower relay.
F12	5 A	Right-hand / left-hand rear seat timer.
F13	25 A	Right-hand rear door control module.
F14	—	Not used
F15	25 A	Right-hand door control module.
F16	—	Not used
F17	15 A	Sunroof.
F18	25 A	Right-hand and left-hand seat heaters.

Right-hand Heelboard Relays

Right-hand heelboard, at the fuse box

Factory name: Right-hand Heelboard RelaysAlso called: relay box, relay panel, heelboard relays, blower motor relay

Relays — Right-hand Heelboard Relays

Relay
Door mirror heater relay
LH blower motor relay
LH lumbar deflate relay
RH blower motor relay

Hover a fuse or relay for details. Always check against the label on your own fuse box — build variations exist within a model year.

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Jaguar XJ8 (X308) 2003 Fuse Box Diagrams

Fuse and relay locations

Engine Compartment Fuse Box (Left-hand Side)

Fuse list — Engine Compartment Fuse Box (Left-hand Side)

Engine Compartment Relays (Outside the Fuse Box)

Relays — Engine Compartment Relays (Outside the Fuse Box)

Engine Management Fuse Box

Fuse list — Engine Management Fuse Box

Luggage Compartment Fuse Box (Electrical Carrier)

Fuse list — Luggage Compartment Fuse Box (Electrical Carrier)

Control Modules Compartment Relays

Relays — Control Modules Compartment Relays

Front Seat Relays

Relays — Front Seat Relays

High Power Protection Module

Fuse list — High Power Protection Module

Left-hand Heelboard Relays

Relays — Left-hand Heelboard Relays

Rear Compartment Fuse Box (Left-hand Heelboard)

Fuse list — Rear Compartment Fuse Box (Left-hand Heelboard)

Rear Compartment Fuse Box (Right-hand Heelboard)

Fuse list — Rear Compartment Fuse Box (Right-hand Heelboard)

Right-hand Heelboard Relays

Relays — Right-hand Heelboard Relays

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