Ford Mondeo (petrol engines). Manual - part 51

Fuses (main fusebox in passenger compartment)

Note: Fuse ratings and circuits are liable to change from year to year. Consult the handbook supplied with the vehicle, or consult a Ford dealer,
for specific information.
Fuse

Rating

Colour

Circuit(s) protected

19

7.5

Brown  . . . . . . . . . . . . . . . . . . . . . . . . .

Heated door mirrors

20

10

Black  . . . . . . . . . . . . . . . . . . . . . . . . . .

Front/rear wiper motor (circuit breaker)

21

30

Light green . . . . . . . . . . . . . . . . . . . . . .

Front electric windows (only)

21

40

Orange  . . . . . . . . . . . . . . . . . . . . . . . . .

Front and rear electric windows

22

7.5

Brown  . . . . . . . . . . . . . . . . . . . . . . . . .

ABS module

23

15

Light blue  . . . . . . . . . . . . . . . . . . . . . . .

Reversing lights

24

15

Light blue  . . . . . . . . . . . . . . . . . . . . . . .

Stop-lights

25

20

Yellow  . . . . . . . . . . . . . . . . . . . . . . . . .

Central locking system/double-locking/anti-theft alarm

26

20

Yellow  . . . . . . . . . . . . . . . . . . . . . . . . .

Foglights

27

15

Light blue  . . . . . . . . . . . . . . . . . . . . . . .

Cigar lighter

28

30

Light green . . . . . . . . . . . . . . . . . . . . . .

Headlight washer system

29

30

Light green . . . . . . . . . . . . . . . . . . . . . .

Heated rear window

30

7.5

Brown  . . . . . . . . . . . . . . . . . . . . . . . . .

Interior lighting and auxiliary warning system

31

7.5

Brown  . . . . . . . . . . . . . . . . . . . . . . . . .

Instrument panel illumination

32

7.5

Brown  . . . . . . . . . . . . . . . . . . . . . . . . .

Radio

33

7.5

Brown  . . . . . . . . . . . . . . . . . . . . . . . . .

Front and rear sidelights (left-hand side)

34

7.5

Brown  . . . . . . . . . . . . . . . . . . . . . . . . .

Interior lighting and digital clock

35

7.5

Brown  . . . . . . . . . . . . . . . . . . . . . . . . .

Front and rear sidelights (right-hand side)

36

30

Light green . . . . . . . . . . . . . . . . . . . . . .

Air bag

37

30

Light green . . . . . . . . . . . . . . . . . . . . . .

Heater blower

38

7.5

Brown  . . . . . . . . . . . . . . . . . . . . . . . . .

Adaptive damping

Relays (auxiliary fusebox in engine compartment)

Relay

Colour

Circuit(s) protected

R1

Green . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Daytime running lights (left-hand-drive, but not all countries) or dim-
dip lights (UK)

R2

Black  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Radiator electric cooling fan (high speed)

R3

Blue (petrol)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Air conditioning cut-out

R3

Brown (Diesel)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Air conditioning in conjunction with Diesel engine

R4

Yellow  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Windscreen heater time delay 

R5

Dark green (petrol) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Radiator electric cooling fan (low speed)

R5

Black (Diesel) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Radiator electric cooling fan (low speed)

R6

Yellow  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Starter solenoid

R7

Brown  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Horns

R8

Brown  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Fuel pump

R9

White  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Dipped beam headlights

R10

White  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Main beam headlights

R11

Brown  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ECU power supply (petrol), cold start (Diesel)

Relays (main fusebox in passenger compartment)

Relay

Colour

Circuit(s) protected

R12

White  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Interior, courtesy and footwell lights

R13

Yellow  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Heated rear window

R14

Yellow  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Heater blower

R15

Green . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Windscreen wiper motor

R16

Black  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Ignition

Auxiliary relays (not in the fuseboxes)

Relay

Colour

Circuit(s) protected

Location

R17

Black  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Diesel glow plug

Battery tray

R18

Black  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

“One-touch down” 

Driver’s door

 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

driver’s window relay

R19

Blue  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Speed control cut-off

Central fuse box bracket the 
below instrument panel

R20

Blue  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Headlight washer system

Bulb module bracket

R21

Orange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Rear screen wiper interval

Bulb module bracket

R22

White  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Foglights (left-hand-drive only)

Interface module bracket

R23

Black  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Direction indicators

Steering column

R24

White  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Anti-theft alarm (left-hand side)

Door lock module bracket

R25

White  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Anti-theft alarm (right-hand side)

Door lock module bracket

R26

Black  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Heated seats

Door lock module bracket

12•2 Body electrical system

Bulbs

Wattage

Type

Headlight main beam  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

55

Halogen

Headlight dipped beam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

55

Halogen

Foglights  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

55

Halogen

Sidelights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5

Wedge

Direction indicator lights  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

21

Bayonet

Side repeater lights  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5

Wedge

Stop-lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

21

Bayonet

Reversing lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

21

Bayonet

Rear fog/tail lights (Saloon and Estate)  . . . . . . . . . . . . . . . . . . . . . . . . . .

21/4

Bayonet

Rear tail light (Saloon and Hatchback)  . . . . . . . . . . . . . . . . . . . . . . . . . .

5

Bayonet

Number plate lights  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5

Festoon

Engine compartment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10

Wedge

Interior lights  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10

Festoon

Reading light  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5

Wedge

Torque wrench settings

Nm

lbf ft

Windscreen wiper motor bolts:

Into old motor (see text)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8

6

Into new motor (see text) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

12

9

Body electrical system  12•3

12

Warning: Before carrying out any
work on the electrical system,
read through the precautions

given in “Safety first!” at the beginning of
this manual.

The electrical system is of 12-volt negative

earth type. Power for the lights and all
electrical accessories is supplied by a
lead/acid battery which is charged by the
alternator.

This Chapter covers repair and service

procedures for the various electrical
components not associated with the engine.
Information on the battery, ignition system,

alternator, and starter motor can be found in
Chapter 5.

All models are fitted with a driver’s air bag,

which is designed to prevent serious chest
and head injuries to the driver during an
accident. A similar bag for the front seat
passenger is also available (see illustration).
The sensor and electronic unit for the air bag
is located next to the steering column inside
the vehicle, and contains a back-up capacitor,
crash sensor, decelerometer, safety sensor,
integrated circuit and microprocessor (see
illustration). The air bag is inflated by a gas
generator, which forces the bag out of the
module cover in the centre of the steering
wheel. A “clock spring” ensures that a good
electrical connection is maintained with the air
bag at all times - as the steering wheel is
turned in each direction, the spring winds and
unwinds.

All UK models are fitted with an alarm

system incorporating a movement sensor and
ignition immobiliser. On Saloon and
Hatchback models, the alarm system horn is
located on the left-hand side of the luggage

1 General information

1.3A  Air bag system components

1  Air bag module (driver’s)
2  Clock spring

3  Diagnostic and sensor unit
4  Air bag indicator light

5  Air bag module 

(passenger’s)

1.3B  Air bag sensor and electronic unit

1  Crash sensor
2  Safety sensor
3  Voltage back-up
4  Application Specific Integrated Circuit
5  Microprocessor

compartment, but on Estate models, it is on
the right-hand side.

Some models are fitted with a headlight

levelling system, which is controlled by a knob
on the facia. On position “0”, the headlights
are in their base position, and on position “5”,
the headlights are in their maximum inclined
angle.

It should be noted that, when portions of

the electrical system are serviced, the cable
should be disconnected from the battery
negative terminal, to prevent electrical shorts
and fires.

Caution: When disconnecting the
battery for work described in the
following Sections, refer to
Chapter 5, Section 1.

Note: Refer to the precautions given in
“Safety first!” and in Section 1 of this Chapter
before starting work. The following tests relate
to testing of the main electrical circuits, and
should not be used to test delicate electronic
circuits (such as engine management systems,
anti-lock braking systems, etc), particularly
where an electronic control module is used.
Also refer to the precautions given in Chapter
5, Section 1.

General

1 A typical electrical circuit consists of an
electrical component, any switches, relays,
motors, fuses, fusible links or circuit breakers
related to that component, and the wiring and
connectors which link the component to both
the battery and the chassis. To help to
pinpoint a problem in an electrical circuit,
wiring diagrams are included at the end of this
manual.
2 Before attempting to diagnose an electrical
fault, first study the appropriate wiring
diagram, to obtain a complete understanding
of the components included in the particular
circuit concerned. The possible sources of a
fault can be narrowed down by noting if other
components related to the circuit are
operating properly. If several components or
circuits fail at one time, the problem is likely to
be related to a shared fuse or earth
connection.
3 Electrical problems usually stem from
simple causes, such as loose or corroded
connections, a faulty earth connection, a
blown fuse, a melted fusible link, or a faulty
relay (refer to Section 3 for details of testing
relays). Visually inspect the condition of all
fuses, wires and connections in a problem
circuit before testing the components. Use
the wiring diagrams to determine which
terminal connections will need to be checked
in order to pinpoint the trouble-spot.
4 The basic tools required for electrical fault-
finding include a circuit tester or voltmeter (a
12-volt bulb with a set of test leads can also

be used for certain tests); an ohmmeter (to
measure resistance and check for continuity);
a battery and set of test leads; and a jumper
wire, preferably with a circuit breaker or fuse
incorporated, which can be used to bypass
suspect wires or electrical components.
Before attempting to locate a problem with
test instruments, use the wiring diagram to
determine where to make the connections.
5 To find the source of an intermittent wiring
fault (usually due to a poor or dirty
connection, or damaged wiring insulation), a
“wiggle” test can be performed on the wiring.
This involves wiggling the wiring by hand to
see if the fault occurs as the wiring is moved.
It should be possible to narrow down the
source of the fault to a particular section of
wiring. This method of testing can be used in
conjunction with any of the tests described in
the following sub-Sections.
6 Apart from problems due to poor
connections, two basic types of fault can
occur in an electrical circuit - open-circuit, or
short-circuit.
7 Open-circuit faults are caused by a break
somewhere in the circuit, which prevents
current from flowing. An open-circuit fault will
prevent a component from working.
8 Short-circuit faults are caused by a “short”
somewhere in the circuit, which allows the
current flowing in the circuit to “escape” along
an alternative route, usually to earth. Short-
circuit faults are normally caused by a
breakdown in wiring insulation, which allows a
feed wire to touch either another wire, or an
earthed component such as the bodyshell. A
short-circuit fault will normally cause the
relevant circuit fuse to blow.

Finding an open-circuit

9 To check for an open-circuit, connect one
lead of a circuit tester or the negative lead of a
voltmeter either to the battery negative
terminal or to a known good earth.
10 Connect the other lead to a connector in
the circuit being tested, preferably nearest to
the battery or fuse. At this point, battery
voltage should be present, unless the lead
from the battery or the fuse itself is faulty
(bearing in mind that some circuits are live
only when the ignition switch is moved to a
particular position).
11 Switch on the circuit, then connect the
tester lead to the connector nearest the circuit
switch on the component side.
12 If voltage is present (indicated either by
the tester bulb lighting or a voltmeter reading,
as applicable), this means that the section of
the circuit between the relevant connector
and the switch is problem-free.
13 Continue to check the remainder of the
circuit in the same fashion.
14 When a point is reached at which no
voltage is present, the problem must lie
between that point and the previous test point
with voltage. Most problems can be traced to
a broken, corroded or loose connection.

Finding a short-circuit

15 To check for a short-circuit, first
disconnect the load(s) from the circuit (loads
are the components which draw current from
a circuit, such as bulbs, motors, heating
elements, etc).
16 Remove the relevant fuse from the circuit,
and connect a circuit tester or voltmeter to the
fuse connections.
17 Switch on the circuit, bearing in mind that
some circuits are live only when the ignition
switch is moved to a particular position.
18 If voltage is present (indicated either by
the tester bulb lighting or a voltmeter reading,
as applicable), this means that there is a
short-circuit.
19 If no voltage is present during this test,
but the fuse still blows with the load(s)
reconnected, this indicates an internal fault in
the load(s).

Finding an earth fault

20 The battery negative terminal is
connected to “earth” - the metal of the
engine/transmission unit and the vehicle body
- and many systems are wired so that they
only receive a positive feed, the current
returning via the metal of the car body. This
means that the component mounting and the
body form part of that circuit. Loose or
corroded mountings can therefore cause a
range of electrical faults, ranging from total
failure of a circuit, to a puzzling partial failure.
In particular, lights may shine dimly (especially
when another circuit sharing the same earth
point is in operation), motors (eg wiper motors
or the radiator cooling fan motor) may run
slowly, and the operation of one circuit may
have an apparently-unrelated effect on
another. Note that on many vehicles, earth
straps are used between certain components,
such as the engine/transmission and the
body, usually where there is no metal-to-
metal contact between components, due to
flexible rubber mountings, etc.
21 To check whether a component is
properly earthed, disconnect the battery (refer
to Chapter 5, Section 1) and connect one lead
of an ohmmeter to a known good earth point.
Connect the other lead to the wire or earth
connection being tested. The resistance
reading should be zero; if not, check the
connection as follows.
22 If an earth connection is thought to be
faulty, dismantle the connection, and clean
both the bodyshell and the wire terminal (or
the component earth connection mating
surface) back to bare metal. Be careful to
remove all traces of dirt and corrosion, then
use a knife to trim away any paint, so that a
clean metal-to-metal joint is made. On
reassembly, tighten the joint fasteners
securely; if a wire terminal is being refitted,
use serrated washers between the terminal
and the bodyshell, to ensure a clean and
secure connection. When the connection is

2 Electrical fault finding -

general information

12•4 Body electrical system

remade, prevent the onset of corrosion in the
future by applying a coat of petroleum jelly or
silicone-based grease, or by spraying on (at
regular intervals) a proprietary ignition sealer
such as Holts Damp Start, or a water-
dispersant lubricant such as Holts Wet Start.

Note: It is important to note that the ignition
switch and the appropriate electrical circuit
must always be switched off before any of the
fuses (or relays) are removed and renewed. In
the event of the fuse/relay unit having to be
removed, the battery earth lead must be
disconnected. When reconnecting the battery,
reference should be made to Chapter 5.
1 Fuses are designed to break a circuit when
a predetermined current is reached, in order
to protect components and wiring which
could be damaged by excessive current flow.
Any excessive current flow will be due to a
fault in the circuit, usually a short-circuit (see
Section 2). The main fusebox, which also
carries some relays, is located inside the
vehicle below the facia panel on the
passenger’s side, and is accessed by a lever
behind the glovebox (see illustration).
2 A central timer module is located on the
bottom of the main fusebox. This module
contains the time control elements for the
heated rear window, interior lights and
intermittent wiper operation. The module also
activates a warning buzzer/chime when the
vehicle is left with the lights switched on, or if
a vehicle fitted with automatic transmission is
not parked in position “P”.
3 The auxiliary fusebox is located on the front
left-hand side of the engine compartment,
and is accessed by unclipping and removing
the cover. The auxiliary fusebox also contains
some relays (see illustration). Each circuit is
identified by numbers on the main fusebox
and on the inside of the auxiliary fusebox
cover. Reference to the fuse chart in the
Specifications at the start of this Chapter will
indicate the circuits protected by each fuse.
Plastic tweezers are attached to the main
fusebox and to the inside face of the auxiliary
fuse and block cover, to remove and fit the
fuses and relays.
4 To remove a fuse, use the tweezers
provided to pull it out of the holder. Slide the
fuse sideways from the tweezers. The wire
within the fuse is clearly visible, and it will be
broken if the fuse is blown (see illustration).
5 Always renew a fuse with one of an
identical rating. Never substitute a fuse of a
higher rating, or make temporary repairs using
wire or metal foil; more serious damage, or
even fire, could result. The fuse rating is
stamped on top of the fuse. Never renew a
fuse more than once without tracing the
source of the trouble.
6 Spare fuses of various current ratings are

provided in the cover of the auxiliary fusebox.
Note that if the vehicle is to be laid up for a
long period, fuse 34 in the main fusebox
should be removed, to prevent the ancillary
electrical components from discharging the
battery.
7 Relays are electrically-operated switches,
which are used in certain circuits. The various
relays can be removed from their respective
locations by carefully pulling them from the
sockets. Each relay in the fuseboxes has a
plastic bar on its upper surface to enable the
use of the tweezers. The locations and

3 Fuses, relays and timer

module - testing and renewal

Body electrical system  12•5

12

3.4  The fuses can be checked visually to

determine if they are blown

3.1  Main fusebox layout

1  Fuse/relay removal tweezers     2  Diode      3  Multi-plug connections

3.3  Auxiliary fusebox layout

1  Fuses 1 to 3

3  Relays R2, R5 and R6

5  Relay sockets for relays R1 and R4

2  Fuses 4 to 8, 11 to 14

4  Relays R7 to R11

6  Diode