Ford Mondeo (petrol engines). Manual - part 68

REF•12

Battery will not hold a charge more than a few days

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Battery defective internally (Chapter 5).

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Battery electrolyte level low (Chapter 1).

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Battery terminal connections loose or corroded (Chapter 5).

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Auxiliary drivebelt worn or incorrectly-adjusted (Chapter 1).

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Alternator not charging at correct output (Chapter 5).

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Alternator or voltage regulator faulty (Chapter 5).

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Short-circuit causing continual battery drain (Chapters 5 and 12).

Ignition (no-charge) warning light remains
illuminated with engine running

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Auxiliary drivebelt broken, worn, or incorrectly-adjusted (Chapter 1).

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Alternator brushes worn, sticking, or dirty (Chapter 5).

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Alternator brush springs weak or broken (Chapter 5).

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Internal fault in alternator or voltage regulator (Chapter 5).

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Broken, disconnected, or loose wiring in charging circuit (Chapter 5).

Ignition (no-charge) warning light fails to come on

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Warning light bulb blown (Chapter 12).

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Broken, disconnected, or loose wiring in warning light circuit
(Chapters 5 and 12).

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Alternator faulty (Chapter 5).

Lights inoperative

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Bulb blown (Chapter 12).

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Corrosion of bulb or bulbholder contacts (Chapter 12).

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Blown fuse (Chapter 12).

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Faulty relay (Chapter 12).

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Broken, loose, or disconnected wiring (Chapter 12).

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Faulty switch (Chapter 12).

Instrument readings inaccurate or erratic

Instrument readings increase with engine speed

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Faulty voltage regulator (Chapter 12).

Fuel or temperature gauges give no reading

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Faulty gauge sender unit (Chapters 3 or 4).

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Wiring open-circuit (Chapter 12).

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Faulty gauge (Chapter 12).

Fuel or temperature gauges give continuous maximum reading

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Faulty gauge sender unit (Chapters 3 or 4).

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Wiring short-circuit (Chapter 12).

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Faulty gauge (Chapter 12).

Horn inoperative, or unsatisfactory in operation

Horn fails to operate

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Blown fuse (Chapter 12).

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Cable or cable connections loose, broken or disconnected (Chapter 12).

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Faulty horn (Chapter 12).

Horn emits intermittent or unsatisfactory sound

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Cable connections loose (Chapter 12).

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Horn mountings loose (Chapter 12).

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Faulty horn (Chapter 12).

Horn operates all the time

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Horn push either earthed or stuck down (Chapter 12).

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Horn cable to horn push earthed (Chapter 12).

Windscreen/tailgate wipers inoperative or
unsatisfactory in operation

Wipers fail to operate, or operate very slowly

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Wiper blades stuck to screen, or linkage seized or binding (Chapter 12).

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Blown fuse (Chapter 12).

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Cable or cable connections loose, broken or disconnected (Chapter 12).

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Faulty relay (Chapter 12).

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Faulty wiper motor (Chapter 12).

Wiper blades sweep over too large or too small an area of
the glass

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Wiper arms incorrectly-positioned on spindles (Chapter 1).

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Excessive wear of wiper linkage (Chapter 1).

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Wiper motor or linkage mountings loose or insecure (Chapter 12).

Wiper blades fail to clean the glass effectively

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Wiper blade rubbers worn or perished (Chapter 1).

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Wiper arm tension springs broken, or arm pivots seized (Chapter 1).

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Insufficient windscreen washer additive to adequately remove road
film (Chapter 1).

Windscreen/tailgate washers inoperative, or
unsatisfactory in operation

One or more washer jets inoperative

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Blocked washer jet (Chapter 1).

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Disconnected, kinked or restricted fluid hose (Chapter 1).

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Insufficient fluid in washer reservoir (Chapter 1).

Washer pump fails to operate

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Broken or disconnected wiring or connections (Chapter 12).

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Blown fuse (Chapter 12).

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Faulty washer switch (Chapter 12).

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Faulty washer pump (Chapter 12).

Washer pump runs for some time before fluid is emitted
from jets

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Faulty one-way valve in fluid supply hose (Chapter 12).

Electric windows inoperative, or unsatisfactory in
operation

Window glass will only move in one direction

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Faulty switch (Chapter 12).

Window glass slow to move

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Incorrectly-adjusted door glass guide channels (Chapter 11).

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Regulator seized or damaged, or in need of lubrication (Chapter 11).

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Door internal components or trim fouling regulator (Chapter 11).

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Faulty motor (Chapter 12).

Window glass fails to move

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Incorrectly-adjusted door glass guide channels (Chapter 11).

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Blown fuse (Chapter 12).

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Faulty relay (Chapter 12).

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Broken or disconnected wiring or connections (Chapter 12).

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Faulty motor (Chapter 12).

Central locking system inoperative, or
unsatisfactory in operation

Complete system failure

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Blown fuse (Chapter 12).

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Faulty relay (Chapter 12).

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Broken or disconnected wiring or connections (Chapter 12).

Latch locks but will not unlock, or unlocks but will not lock

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Faulty master switch (Chapter 11).

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Broken or disconnected latch operating rods or levers (Chapter 11).

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Faulty relay (Chapter 12).

One lock motor fails to operate

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Broken or disconnected wiring or connections (Chapter 12).

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Faulty lock motor (Chapter 11).

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Broken, binding or disconnected latch operating rods or levers
(Chapter 11).

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Fault in door latch (Chapter 11).

Fault Finding

10 Electrical system

Note: For problems associated with the starting system, refer to the faults listed under “Engine” earlier in this Section.

REF•13

Glossary of Technical Terms

A

ABS (Anti-lock brake system)

A system,

usually electronically controlled, that senses
incipient wheel lockup during braking and
relieves hydraulic pressure at wheels that are
about to skid.
Air bag  An inflatable bag hidden in the
steering wheel (driver’s side) or the dash or
glovebox (passenger side). In a head-on
collision, the bags inflate, preventing the
driver and front passenger from being thrown
forward into the steering wheel or windscreen.
Air cleaner

A metal or plastic housing,

containing a filter element, which removes
dust and dirt from the air being drawn into the
engine.
Air filter element The actual filter in an air
cleaner system, usually manufactured from
pleated paper and requiring renewal at regular
intervals.

Allen key A hexagonal wrench which fits into
a recessed hexagonal hole.
Alligator clip

A long-nosed spring-loaded

metal clip with meshing teeth. Used to make
temporary electrical connections.
Alternator

A component in the electrical

system which converts mechanical energy
from a drivebelt into electrical energy to
charge the battery and to operate the starting
system, ignition system and electrical
accessories. 
Ampere (amp) A unit of measurement for the
flow of electric current. One amp is the
amount of current produced by one volt
acting through a resistance of one ohm.
Anaerobic sealer

A substance used to

prevent bolts and screws from loosening.
Anaerobic means that it does not require
oxygen for activation. The Loctite brand is
widely used.
Antifreeze

A substance (usually ethylene

glycol) mixed with water, and added to a
vehicle’s cooling system, to prevent freezing
of the coolant in winter. Antifreeze also
contains chemicals to inhibit corrosion and
the formation of rust and other deposits that
would tend to clog the radiator and coolant
passages and reduce cooling efficiency.
Anti-seize compound

A coating that

reduces the risk of seizing on fasteners that
are subjected to high temperatures, such as
exhaust manifold bolts and nuts.
Asbestos A natural fibrous mineral with great
heat resistance, commonly used in the
composition of brake friction materials.

Asbestos is a health hazard and the dust
created by brake systems should never be
inhaled or ingested.
Axle A shaft on which a wheel revolves, or
which revolves with a wheel. Also, a solid
beam that connects the two wheels at one
end of the vehicle. An axle which also
transmits power to the wheels is known as a
live axle.
Axleshaft

A single rotating shaft, on either

side of the differential, which delivers power
from the final drive assembly to the drive
wheels. Also called a driveshaft or a halfshaft.

B

Ball bearing

An anti-friction bearing

consisting of a hardened inner and outer race
with hardened steel balls between two races.
Bearing The curved surface on a shaft or in a
bore, or the part assembled into either, that
permits relative motion between them with
minimum wear and friction.

Big-end bearing The bearing in the end of
the connecting rod that’s attached to the
crankshaft.
Bleed nipple

A valve on a brake wheel

cylinder, caliper or other hydraulic component
that is opened to purge the hydraulic system
of air. Also called a bleed screw.
Brake bleeding Procedure for removing air
from lines of a hydraulic brake system.

Brake disc The component of a disc brake
that rotates with the wheels.

Brake drum The component of a drum brake
that rotates with the wheels.
Brake linings

The friction material which

contacts the brake disc or drum to retard the
vehicle’s speed. The linings are bonded or
riveted to the brake pads or shoes.
Brake pads

The replaceable friction pads

that pinch the brake disc when the brakes are
applied. Brake pads consist of a friction
material bonded or riveted to a rigid backing
plate.
Brake shoe The crescent-shaped carrier to
which the brake linings are mounted and
which forces the lining against the rotating
drum during braking.
Braking systems

For more information on

braking systems, consult the Haynes
Automotive Brake Manual.
Breaker bar

A long socket wrench handle

providing greater leverage.
Bulkhead

The insulated partition between

the engine and the passenger compartment.

C

Caliper The non-rotating part of a disc-brake
assembly that straddles the disc and carries
the brake pads. The caliper also contains the
hydraulic components that cause the pads to
pinch the disc when the brakes are applied. A
caliper is also a measuring tool that can be set
to measure inside or outside dimensions of an
object.
Camshaft A rotating shaft on which a series
of cam lobes operate the valve mechanisms.
The camshaft may be driven by gears, by
sprockets and chain or by sprockets and a
belt.
Canister

A container in an evaporative

emission control system; contains activated
charcoal granules to trap vapours from the
fuel system.

Carburettor A device which mixes fuel with
air in the proper proportions to provide a
desired power output from a spark ignition
internal combustion engine.
Castellated Resembling the parapets along
the top of a castle wall. For example, a
castellated balljoint stud nut.
Castor In wheel alignment, the backward or
forward tilt of the steering axis. Castor is
positive when the steering axis is inclined
rearward at the top.

Canister

Brake bleeding

Bearing

Air filter

REF•14

Glossary of Technical Terms

Catalytic converter A silencer-like device in
the exhaust system which converts certain
pollutants in the exhaust gases into less
harmful substances.

Circlip

A ring-shaped clip used to prevent

endwise movement of cylindrical parts and
shafts. An internal circlip is installed in a
groove in a housing; an external circlip fits into
a groove on the outside of a cylindrical piece
such as a shaft.
Clearance

The amount of space between

two parts. For example, between a piston and
a cylinder, between a bearing and a journal,
etc.
Coil spring A spiral of elastic steel found in
various sizes throughout a vehicle, for
example as a springing medium in the
suspension and in the valve train.
Compression

Reduction in volume, and

increase in pressure and temperature, of a
gas, caused by squeezing it into a smaller
space.
Compression ratio The relationship between
cylinder volume when the piston is at top
dead centre and cylinder volume when the
piston is at bottom dead centre.
Constant velocity (CV) joint

A type of

universal joint that cancels out vibrations
caused by driving power being transmitted
through an angle.
Core plug A disc or cup-shaped metal device
inserted in a hole in a casting through which
core was removed when the casting was
formed. Also known as a freeze plug or
expansion plug. 
Crankcase

The lower part of the engine

block in which the crankshaft rotates.
Crankshaft

The main rotating member, or

shaft, running the length of the crankcase,
with offset “throws” to which the connecting
rods are attached.

Crocodile clip See Alligator clip

D

Diagnostic code Code numbers obtained by
accessing the diagnostic mode of an engine
management computer. This code can be
used to determine the area in the system
where a malfunction may be located.
Disc brake A brake design incorporating a
rotating disc onto which brake pads are
squeezed. The resulting friction converts the
energy of a moving vehicle into heat.
Double-overhead cam (DOHC)

An engine

that uses two overhead camshafts, usually
one for the intake valves and one for the
exhaust valves.
Drivebelt(s)

The belt(s) used to drive

accessories such as the alternator, water
pump, power steering pump, air conditioning
compressor, etc. off the crankshaft pulley.

Driveshaft

Any shaft used to transmit

motion. Commonly used when referring to the
axleshafts on a front wheel drive vehicle.
Drum brake A type of brake using a drum-
shaped metal cylinder attached to the inner
surface of the wheel. When the brake pedal is
pressed, curved brake shoes with friction
linings press against the inside of the drum to
slow or stop the vehicle.

E

EGR valve A valve used to introduce exhaust
gases into the intake air stream.
Electronic control unit (ECU)

A computer

which controls (for instance) ignition and fuel
injection systems, or an anti-lock braking
system. For more information refer to the
Haynes Automotive Electrical and Electronic
Systems Manual.
Electronic Fuel Injection (EFI) A computer
controlled fuel system that distributes fuel
through an injector located in each intake port
of the engine.
Emergency brake

A braking system,

independent of the main hydraulic system,
that can be used to slow or stop the vehicle if
the primary brakes fail, or to hold the vehicle
stationary even though the brake pedal isn’t
depressed. It usually consists of a hand lever
that actuates either front or rear brakes
mechanically through a series of cables and
linkages. Also known as a handbrake or
parking brake.

Endfloat

The amount of lengthwise

movement between two parts. As applied to a
crankshaft, the distance that the crankshaft
can move forward and back in the cylinder
block.

Engine management system (EMS)

A

computer controlled system which manages
the fuel injection and the ignition systems in
an integrated fashion.

Exhaust manifold

A part with several

passages through which exhaust gases leave
the engine combustion chambers and enter
the exhaust pipe.

F

Fan clutch

A viscous (fluid) drive coupling

device which permits variable engine fan
speeds in relation to engine speeds.

Feeler blade A thin strip or blade of hardened
steel, ground to an exact thickness, used to
check or measure clearances between parts.

Firing order The order in which the engine
cylinders fire, or deliver their power strokes,
beginning with the number one cylinder.

Flywheel  A heavy spinning wheel in which
energy is absorbed and stored by means of
momentum. On cars, the flywheel is attached
to the crankshaft to smooth out firing
impulses.

Free play The amount of travel before any
action takes place. The “looseness” in a
linkage, or an assembly of parts, between the
initial application of force and actual
movement. For example, the distance the
brake pedal moves before the pistons in the
master cylinder are actuated.

Fuse

An electrical device which protects a

circuit against accidental overload. The typical
fuse contains a soft piece of metal which is
calibrated to melt at a predetermined current
flow (expressed as amps) and break the
circuit.

Fusible link

A circuit protection device

consisting of a conductor surrounded by
heat-resistant insulation. The conductor is
smaller than the wire it protects, so it acts as
the weakest link in the circuit. Unlike a blown
fuse, a failed fusible link must frequently be
cut from the wire for replacement.

Catalytic converter

Crankshaft assembly

Accessory drivebelts

Feeler blade

REF•15

Glossary of Technical Terms

G

Gap

The distance the spark must travel in

jumping from the centre electrode to the side
electrode in a spark plug. Also refers to the
spacing between the points in a contact
breaker assembly in a conventional points-
type ignition, or to the distance between the
reluctor or rotor and the pickup coil in an
electronic ignition.

Gasket Any thin, soft material - usually cork,
cardboard, asbestos or soft metal - installed
between two metal surfaces to ensure a good
seal. For instance, the cylinder head gasket
seals the joint between the block and the
cylinder head.

Gauge An instrument panel display used to
monitor engine conditions. A gauge with a
movable pointer on a dial or a fixed scale is an
analogue gauge. A gauge with a numerical
readout is called a digital gauge. 

H

Halfshaft

A rotating shaft that transmits

power from the final drive unit to a drive
wheel, usually when referring to a live rear
axle.
Harmonic balancer

A device designed to

reduce torsion or twisting vibration in the
crankshaft. May be incorporated in the
crankshaft pulley. Also known as a vibration
damper.
Hone

An abrasive tool for correcting small

irregularities or differences in diameter in an
engine cylinder, brake cylinder, etc.
Hydraulic tappet

A tappet that utilises

hydraulic pressure from the engine’s
lubrication system to maintain zero clearance
(constant contact with both camshaft and
valve stem). Automatically adjusts to variation
in valve stem length. Hydraulic tappets also
reduce valve noise.

I

Ignition timing

The moment at which the

spark plug fires, usually expressed in the
number of crankshaft degrees before the
piston reaches the top of its stroke.
Inlet manifold

A tube or housing with

passages through which flows the air-fuel
mixture (carburettor vehicles and vehicles with
throttle body injection) or air only (port fuel-
injected vehicles) to the port openings in the
cylinder head.

J

Jump start Starting the engine of a vehicle
with a discharged or weak battery by
attaching jump leads from the weak battery to
a charged or helper battery.

L

Load Sensing Proportioning Valve (LSPV) A
brake hydraulic system control valve that
works like a proportioning valve, but also
takes into consideration the amount of weight
carried by the rear axle.
Locknut A nut used to lock an adjustment
nut, or other threaded component, in place.
For example, a locknut is employed to keep
the adjusting nut on the rocker arm in
position.
Lockwasher A form of washer designed to
prevent an attaching nut from working loose.

M

MacPherson strut

A type of front

suspension system devised by Earle
MacPherson at Ford of England. In its original
form, a simple lateral link with the anti-roll bar
creates the lower control arm. A long strut - an
integral coil spring and shock absorber - is
mounted between the body and the steering
knuckle. Many modern so-called MacPherson
strut systems use a conventional lower A-arm
and don’t rely on the anti-roll bar for location.
Multimeter An electrical test instrument with
the capability to measure voltage, current and
resistance.

N

NOx

Oxides of Nitrogen. A common toxic

pollutant emitted by petrol and diesel engines
at higher temperatures. 

O

Ohm

The unit of electrical resistance. One

volt applied to a resistance of one ohm will
produce a current of one amp.
Ohmmeter

An instrument for measuring

electrical resistance.
O-ring

A type of sealing ring made of a

special rubber-like material; in use, the O-ring
is compressed into a groove to provide the
sealing action.
Overhead cam (ohc) engine An engine with
the camshaft(s) located on top of the cylinder
head(s).

Overhead valve (ohv) engine An engine with
the valves located in the cylinder head, but
with the camshaft located in the engine block.
Oxygen sensor

A device installed in the

engine exhaust manifold, which senses the
oxygen content in the exhaust and converts
this information into an electric current. Also
called a Lambda sensor.

P

Phillips screw A type of screw head having a
cross instead of a slot for a corresponding
type of screwdriver.
Plastigage

A thin strip of plastic thread,

available in different sizes, used for measuring
clearances. For example, a strip of Plastigage
is laid across a bearing journal. The parts are
assembled and dismantled; the width of the
crushed strip indicates the clearance between
journal and bearing.

Propeller shaft

The long hollow tube with

universal joints at both ends that carries
power from the transmission to the differential
on front-engined rear wheel drive vehicles.
Proportioning valve

A hydraulic control

valve which limits the amount of pressure to
the rear brakes during panic stops to prevent
wheel lock-up.

R

Rack-and-pinion steering A steering system
with a pinion gear on the end of the steering
shaft that mates with a rack (think of a geared
wheel opened up and laid flat). When the
steering wheel is turned, the pinion turns,
moving the rack to the left or right. This
movement is transmitted through the track
rods to the steering arms at the wheels.
Radiator A liquid-to-air heat transfer device
designed to reduce the temperature of the
coolant in an internal combustion engine
cooling system. 
Refrigerant Any substance used as a heat
transfer agent in an air-conditioning system.
R-12 has been the principle refrigerant for
many years; recently, however, manufacturers
have begun using R-134a, a non-CFC
substance that is considered less harmful to
the ozone in the upper atmosphere.
Rocker arm A lever arm that rocks on a shaft
or pivots on a stud. In an overhead valve
engine, the rocker arm converts the upward
movement of the pushrod into a downward
movement to open a valve.

Adjusting spark plug gap

Plastigage

Gasket