wiring FORD SIERRA 1992 2.G Reference Workshop Manual

headings denoting various components or systems, such as Engine,
Cooling system, etc. The Chapter and/or Section which deals with the
problem is also shown in brackets. Whatever the fault, certain basic
principles apply. These are as follows:
Verify the fault. This is simply a matter of being sure that you know
what the symptoms are before starting work. This is particularly
important if you are investigating a fault for someone else, who may
not have described it very accurately.
Don’t overlook the obvious. For example, if the vehicle won’t start, is
there fuel in the tank? (Don’t take anyone else’s word on this particular
point, and don’t trust the fuel gauge either!) If an electrical fault is
indicated, look for loose or broken wires before digging out the test
gear.Cure the disease, not the symptom. Substituting a flat battery with a
fully-charged one will get you off the hard shoulder, but if the
underlying cause is not attended to, the new battery will go the same
way. Similarly, changing oil-fouled spark plugs for a new set will get
you moving again, but remember that the reason for the fouling (if it
wasn’t simply an incorrect grade of plug) will have to be established
and corrected.
Don’t take anything for granted. Particularly, don’t forget that a
“new” component may itself be defective (especially if it’s been rattling
around in the boot for months), and don’t leave components out of a
fault diagnosis sequence just because they are new or recently-fitted.
When you do finally diagnose a difficult fault, you’ll probably realise
that all the evidence was there from the start.
Engine fails to rotate when attempting to start
MBattery terminal connections loose or corroded (Chapter 1).
MBattery discharged or faulty (Chapter 5).
MBroken, loose or disconnected wiring in the starting circuit (Chapter 5).
MDefective starter solenoid or switch (Chapter 5).
MDefective starter motor (Chapter 5).
MStarter pinion or flywheel/driveplate ring gear teeth loose or broken
(Chapters 2 or 5).
MEngine earth strap broken or disconnected.
Starter motor turns engine slowly
MPartially-discharged battery (recharge, use jump leads, or push start)
(Chapter 5).
MBattery terminals loose or corroded (Chapter 1).
MBattery earth to body defective (Chapter 5).
MEngine earth strap loose.
MStarter motor (or solenoid) wiring loose (Chapter 5).
MStarter motor internal fault (Chapter 5).
Engine rotates, but will not start
MFuel pump inertia switch tripped (electric pump) (Chapter 4).
MFuel tank empty.
MBattery discharged (engine rotates slowly) (Chapter 5).
MBattery terminal connections loose or corroded (Chapter 1).
MIgnition components damp or damaged (Chapters 1 and 5).
MBroken, loose or disconnected wiring in the ignition circuit (Chapters 1
and 5).
MWorn, faulty or incorrectly-gapped spark plugs (Chapter 1).
MFuel injection system fault (Chapter 4).
MMajor mechanical failure (eg broken timing chain) (Chapter 2).
Engine difficult to start when cold
MBattery discharged (Chapter 5).
MBattery terminal connections loose or corroded (Chapter 1).
MWorn, faulty or incorrectly-gapped spark plugs (Chapter 1).
MFuel injection system fault (Chapter 4).
MOther ignition system fault (Chapters 1 and 5).
MLow cylinder compressions (Chapter 2).
Engine difficult to start when hot
MAir filter element dirty or clogged (Chapter 1).
MFuel injection system fault (Chapter 4).
MLow cylinder compressions (Chapter 2).
Starter motor noisy or excessively-rough in
engagement
MStarter pinion or flywheel/driveplate ring gear teeth loose or broken
(Chapters 2 or 5).
MStarter motor mounting bolts loose or missing (Chapter 5).
MStarter motor internal components worn or damaged (Chapter 5).
Engine starts, but stops immediately
MLoose or faulty electrical connections in the ignition circuit
(Chapters 1 and 5).
MVacuum leak at the throttle body or inlet manifold (Chapter 4).
MFuel injection system fault (Chapter 4).
Engine idles erratically
MIncorrectly-adjusted idle speed (Chapter 4).
MAir filter element clogged (Chapter 1).
MVacuum leak at the throttle body, inlet manifold or associated
hoses (Chapter 4).
MWorn, faulty or incorrectly-gapped spark plugs (Chapter 1).
MUneven or low cylinder compressions (Chapter 2).
MCamshaft lobes worn (Chapter 2).
MFuel injection system fault (Chapter 4).
Engine misfires at idle speed
MWorn, faulty or incorrectly-gapped spark plugs (Chapter 1).
MFaulty spark plug HT leads (Chapter 5).
MVacuum leak at the throttle body, inlet manifold or associated
hoses (Chapter 4).
MFuel injection system fault (Chapter 4).
MDistributor cap cracked or tracking internally, where applicable
(Chapter 5).
MUneven or low cylinder compressions (Chapter 2).
MDisconnected, leaking, or perished crankcase ventilation hoses
(Chapter 4).
Engine misfires throughout the driving speed range
MFuel filter choked (Chapter 1).
MFuel pump faulty, or delivery pressure low (Chapter 4).
MFuel tank vent blocked, or fuel pipes restricted (Chapter 4).
MVacuum leak at the throttle body, inlet manifold or associated
hoses (Chapter 4).
MWorn, faulty or incorrectly-gapped spark plugs (Chapter 1).
MFaulty spark plug HT leads (Chapter 5).
MDistributor cap cracked or tracking internally, where applicable
(Chapter 5).
MFaulty ignition coil (Chapter 5).
MUneven or low cylinder compressions (Chapter 2).
MFuel injection system fault (Chapter 4).
Engine hesitates on acceleration
MWorn, faulty or incorrectly-gapped spark plugs (Chapter 1).
MVacuum leak at the throttle body, inlet manifold or associated
hoses (Chapter 4).
MFuel injection system fault (Chapter 4).
Engine stalls
MVacuum leak at the throttle body, inlet manifold or associated
hoses (Chapter 4).
REF•12Fault diagnosis
Engine

Brakes binding
MSeized brake caliper piston(s) (Chapter 10).
MIncorrectly-adjusted handbrake mechanism (Chapter 10).
MFaulty master cylinder (Chapter 10).
Rear wheels locking under normal braking
MSeized brake caliper piston(s) (Chapter 10).
MFaulty brake pressure regulator (Chapter 10).
Note:For problems associated with the starting system, refer to the
faults listed under “Engine” earlier in this Section.
Battery will not hold a charge for more than a few
days
MBattery defective internally (Chapter 5).
MBattery electrolyte level low - where applicable (Chapter 1).
MBattery terminal connections loose or corroded (Chapter 1).
MAuxiliary drivebelt worn - or incorrectly adjusted (Chapter 1).
MAlternator not charging at correct output (Chapter 5).MAlternator or voltage regulator faulty (Chapter 5).
MShort-circuit causing continual battery drain (Chapters 5 and 13).
Ignition/no-charge warning light remains illuminated
with engine running
MAuxiliary drivebelt broken, worn, or incorrectly adjusted (Chapter 1).
MAlternator brushes worn, sticking, or dirty (Chapter 5).
MAlternator brush springs weak or broken (Chapter 5).
MInternal fault in alternator or voltage regulator (Chapter 5).
MBroken, disconnected, or loose wiring in charging circuit (Chapter 5). Note:Before diagnosing suspension or steering faults, be sure that the
trouble is not due to incorrect tyre pressures, mixtures of tyre types, or
binding brakes.
Vehicle pulls to one side
MDefective tyre (Chapter 1).
MExcessive wear in suspension or steering components (Chapters 1
and 11).
MIncorrect front wheel alignment (Chapter 11).
MAccident damage to steering or suspension components (Chapters 1
and 11).
Wheel wobble and vibration
MFront roadwheels out of balance (vibration felt mainly through the
steering wheel) (Chapter 11).
MRear roadwheels out of balance (vibration felt throughout the
vehicle) (Chapter 11).
MRoadwheels damaged or distorted (Chapter 11).
MFaulty or damaged tyre (Chapter 1).
MWorn steering or suspension joints, bushes or components
(Chapters 1 and 11).
MWheel bolts loose (Chapter 11).
Excessive pitching and/or rolling around corners, or
during braking
MDefective shock absorbers (Chapters 1 and 11).
MBroken or weak coil spring and/or suspension component
(Chapters 1 and 11).
MWorn or damaged anti-roll bar or mountings (Chapter 11).
Wandering or general instability
MIncorrect front wheel alignment (Chapter 11).
MWorn steering or suspension joints, bushes or components
(Chapters 1 and 11).
MRoadwheels out of balance (Chapter 11).
MFaulty or damaged tyre (Chapter 1).
MWheel bolts loose (Chapter 11).
MDefective shock absorbers (Chapters 1 and 11).
Excessively-stiff steering
MLack of steering gear lubricant (Chapter 11).
MSeized track rod end balljoint or suspension balljoint (Chapters 1
and 11).MBroken or incorrectly adjusted auxiliary drivebelt (Chapter 1).
MIncorrect front wheel alignment (Chapter 11).
MSteering rack or column bent or damaged (Chapter 11).
Excessive play in steering
MWorn steering column universal joint(s) (Chapter 11).
MWorn steering track rod end balljoints (Chapters 1 and 11).
MWorn rack-and-pinion steering gear (Chapter 11).
MWorn steering or suspension joints, bushes or components
(Chapters 1 and 11).
Lack of power assistance
MBroken or incorrectly-adjusted auxiliary drivebelt (Chapter 1).
MIncorrect power steering fluid level (Chapter 1).
MRestriction in power steering fluid hoses (Chapter 11).
MFaulty power steering pump (Chapter 11).
MFaulty rack-and-pinion steering gear (Chapter 11).
Tyre wear excessive
Tyres worn on inside or outside edges
MTyres under-inflated (wear on both edges) (Chapter 1).
MIncorrect camber or castor angles (wear on one edge only)
(Chapter 11).
MWorn steering or suspension joints, bushes or components
(Chapters 1 and 11).
MExcessively-hard cornering.
MAccident damage.
Tyre treads exhibit feathered edges
MIncorrect toe setting (Chapter 11).
Tyres worn in centre of tread
MTyres over-inflated (Chapter 1).
Tyres worn on inside and outside edges
MTyres under-inflated (Chapter 1).
MWorn shock absorbers (Chapters 1 and 11).
Tyres worn unevenly
MTyres out of balance (Chapter 1).
MExcessive wheel or tyre run-out (Chapter 1).
MWorn shock absorbers (Chapters 1 and 11).
MFaulty tyre (Chapter 1).
REF•16Fault diagnosis
Steering and suspension
Electrical system

Ignition/no-charge warning light fails to come on
MWarning light bulb blown (Chapter 13).
MBroken, disconnected, or loose wiring in warning light circuit
(Chapter 13).
MAlternator faulty (Chapter 5).
Lights inoperative
MBulb blown (Chapter 13).
MCorrosion of bulb or bulbholder contacts (Chapter 13).
MBlown fuse (Chapter 13).
MFaulty relay (Chapter 13).
MBroken, loose, or disconnected wiring (Chapter 13).
MFaulty switch (Chapter 13).
Instrument readings inaccurate or erratic
Instrument readings increase with engine speed
MFaulty voltage regulator (Chapter 13).
Fuel or temperature gauges give no reading
MFaulty gauge sender unit (Chapters 4 and 5).
MWiring open-circuit (Chapter 13).
MFaulty gauge (Chapter 13).
Fuel or temperature gauges give continuous maximum
reading
MFaulty gauge sender unit (Chapters 4 and 5).
MWiring short-circuit (Chapter 13).
MFaulty gauge (Chapter 13).
Horn inoperative, or unsatisfactory in operation
Horn operates all the time
MHorn contacts permanently bridged or horn push stuck down
(Chapter 13).
Horn fails to operate
MBlown fuse (Chapter 13).
MCable or cable connections loose, broken or disconnected
(Chapter 13).
MFaulty horn (Chapter 13).
Horn emits intermittent or unsatisfactory sound
MCable connections loose (Chapter 13).
MHorn mountings loose (Chapter 13).
MFaulty horn (Chapter 13).
Windscreen/tailgate wipers inoperative, or
unsatisfactory in operation
Wipers fail to operate, or operate very slowly
MWiper blades stuck to screen, or linkage seized or binding
(Chapters 1 and 13).
MBlown fuse (Chapter 13).
MCable or cable connections loose, broken or disconnected
(Chapter 13).
MFaulty relay (Chapter 13).
MFaulty wiper motor (Chapter 13).
Wiper blades sweep over too large or too small an area of
the glass
MWiper arms incorrectly positioned on spindles (Chapter 1).
MExcessive wear of wiper linkage (Chapter 13).
MWiper motor or linkage mountings loose or insecure (Chapter 13).
Wiper blades fail to clean the glass effectively
MWiper blade rubbers worn or perished (Chapter 1).
MWiper arm tension springs broken, or arm pivots seized (Chapter 13).
MInsufficient windscreen washer additive to adequately remove road
film (Chapter 1).
Windscreen/tailgate washers inoperative, or
unsatisfactory in operation
One or more washer jets inoperative
MBlocked washer jet (Chapter 1).
MDisconnected, kinked or restricted fluid hose (Chapter 13).
MInsufficient fluid in washer reservoir (Chapter 1).
Washer pump fails to operate
MBroken or disconnected wiring or connections (Chapter 13).
MBlown fuse (Chapter 13).
MFaulty washer switch (Chapter 13).
MFaulty washer pump (Chapter 13).
Washer pump runs for some time before fluid is emitted
from jets
MFaulty one-way valve in fluid supply hose (Chapter 13).
Electric windows inoperative, or unsatisfactory in
operation
Window glass will only move in one direction
MFaulty switch (Chapter 13).
Window glass slow to move
MRegulator seized or damaged, or in need of lubrication (Chapter 12).
MDoor internal components or trim fouling regulator (Chapter 12).
MFaulty motor (Chapter 12).
Window glass fails to move
MBlown fuse (Chapter 13).
MFaulty relay (Chapter 13).
MBroken or disconnected wiring or connections (Chapter 13).
MFaulty motor (Chapter 13).
Central locking system inoperative, or unsatisfactory
in operation
Complete system failure
MBlown fuse (Chapter 13).
MFaulty relay (Chapter 13).
MBroken or disconnected wiring or connections (Chapter 13).
Latch locks but will not unlock, or unlocks but will not lock
MFaulty switch (Chapter 13).
MBroken or disconnected latch operating rods or levers (Chapter 12).
MFaulty relay (Chapter 13).
One solenoid/motor fails to operate
MBroken or disconnected wiring or connections (Chapter 13).
MFaulty solenoid/motor (Chapter 12).
MBroken, binding or disconnected latch operating rods or levers
(Chapter 12).
MFault in door latch (Chapter 12).
Fault diagnosisREF•17
REF

REF•22Glossary of Technical terms
automatic transmission, a switch that
prevents starting if the vehicle is not in Neutral
or Park.
StrutSee MacPherson strut.
TTappetA cylindrical component which
transmits motion from the cam to the valve
stem, either directly or via a pushrod and
rocker arm. Also called a cam follower.
ThermostatA heat-controlled valve that
regulates the flow of coolant between the
cylinder block and the radiator, so maintaining
optimum engine operating temperature. A
thermostat is also used in some air cleaners in
which the temperature is regulated.
Thrust bearingThe bearing in the clutch
assembly that is moved in to the release levers
by clutch pedal action to disengage the
clutch. Also referred to as a release bearing.
Timing beltA toothed belt which drives the
camshaft. Serious engine damage may result
if it breaks in service.
Timing chainA chain which drives the
camshaft.
Toe-inThe amount the front wheels are
closer together at the front than at the rear. On
rear wheel drive vehicles, a slight amount of
toe-in is usually specified to keep the front
wheels running parallel on the road by
offsetting other forces that tend to spread the
wheels apart.
Toe-outThe amount the front wheels are
closer together at the rear than at the front. Onfront wheel drive vehicles, a slight amount of
toe-out is usually specified.
ToolsFor full information on choosing and
using tools, refer to the Haynes Automotive
Tools Manual.
TracerA stripe of a second colour applied to
a wire insulator to distinguish that wire from
another one with the same colour insulator.
Tune-upA process of accurate and careful
adjustments and parts replacement to obtain
the best possible engine performance.
TurbochargerA centrifugal device, driven by
exhaust gases, that pressurises the intake air.
Normally used to increase the power output
from a given engine displacement, but can
also be used primarily to reduce exhaust
emissions (as on VW’s “Umwelt” Diesel
engine).
UUniversal joint or U-jointA double-pivoted
connection for transmitting power from a
driving to a driven shaft through an angle. A U-
joint consists of two Y-shaped yokes and a
cross-shaped member called the spider.
VValveA device through which the flow of
liquid, gas, vacuum, or loose material in bulk
may be started, stopped, or regulated by a
movable part that opens, shuts, or partiallyobstructs one or more ports or passageways.
A valve is also the movable part of such a
device.
Valve clearanceThe clearance between the
valve tip (the end of the valve stem) and the
rocker arm or tappet. The valve clearance is
measured when the valve is closed.
Vernier caliperA precision measuring
instrument that measures inside and outside
dimensions. Not quite as accurate as a
micrometer, but more convenient.
ViscosityThe thickness of a liquid or its
resistance to flow.
VoltA unit for expressing electrical “pressure”
in a circuit. One volt that will produce a current
of one ampere through a resistance of one
ohm.
WWeldingVarious processes used to join metal
items by heating the areas to be joined to a
molten state and fusing them together. For
more information refer to the Haynes
Automotive Welding Manual.
Wiring diagramA drawing portraying the
components and wires in a vehicle’s electrical
system, using standardised symbols. For
more information refer to the Haynes
Automotive Electrical and Electronic Systems
Manual.

Pedals:
accelerator - 4A•8
brake - 10•22
clutch - 6•2
Pierburg 2V carburettor- 1•12, 4A•14
Pipes/hoses (braking system)- 10•19
Pistons- 2A•22, 2B•17, 2C•21
Plastic components- 12•3
Plugs- 1•2, 1•14, 5•12
Power operated windows- 13•18
Power steering fluid- 0•17
Power steering fluid level- 0•14
Power steering fluid hoses-11•18
Power steering pump- 11•18
Power steering system bleeding- 11•18
Pressure switch (hydraulic unit)- 10•17
Propeller shaft- 8•1 et seq
centre bearing - 8•2
fault diagnosis - REF•11, REF•15
front rubber coupling - 8•3
removal and refitting - 8•2
vibration damper - 8•4
Pulse-air system- 4B•10
Punctures- 0•6
RRadiator- 1•16, 3•3
Radiator cooling fan- 3•7
Radiator grille- 12•14
Radio/cassette player- 13•21
Rear axle- 9•7, 9•8, 11•13
Relays- 13•3
Release bearing (clutch)- 6•5
Repair procedures- REF •4
Respraying- 12•2
Reversing lamp switch- 7B•6, 13•4
Roadtest- 1•17
Roadwheel check- 1•11
Roll bars- 11•6, 11•13
Rotor arm- 5•14, 5•15
Routine maintenance and servicing- 1•1 et seq
Routine maintenance procedures- 1•9
Routine maintenance schedule- 1•3
SSafety first!- 0•5
Scratches- 12•2
Seat belts- 1•11, 12•21
Seat heating pad- 13•19
Seats- 12•19
Selector rod- 7B•5
Sender unit fuel level- 4A•7, 4B•7
Sender units coolant temperature- 3•8
Servicing -see Routine maintenance
Servo unit (braking system)- 10•14
Shock absorber- 11•9
Shoes (brake)- 10•6
Short-circuit finding- 13•3
Spare parts- REF•3
Spark plugs- 1•2, 1•14, 5•12
Speakers- 13•20Specifications- see start of relevant Chapter
Speedometer- 13•8
Speedometer cable- 13•11
Spoiler- 12•6
Starter inhibitor switch- 7B•6
Starter motor- 5•8
Steering- 11•1 et seq
check -1•17, 1•18
column/adjustment - 11•15
fault diagnosis - REF•11, REF•16
gear - 11•16, 11•18
hoses - 11•18
power steering system bleeding - 11•18
pump - 11•18
tie-rod end - 11•18
wheel - 11•14
wheel alignment - 11•1, 11•19
Sump- 2A•20, 2B•15, 2C•19
Sunroof- 12•15, 13•6
Support struts (tailgate)- 12•6
Suspension and steering- 11•1 et seq
anti-roll bars - 11•6, 11•13
check - 1•17, 1•18
coil spring (rear) - 11•10
crossmember (front) - 11•3
fault diagnosis - REF•11, REF•16
hub carrier (front) - 11•5
leaf springs - 11•13
lower arm (front/rear) - 11•4, 11•7, 11•8
mountings - 11•12
rear axle assembly - 11•13
shock absorber - 11•9
strut (front) - 11•4
wheel bearings - 11•6, 11•10
Switches:
brake lamp - 13•6
cooling system - 3•8
courtesy lamp - 13•5
direction indicator - 13•4
electric door mirror - 13•5
facia panel - 13•4
handbrake warning lamp - 13•6
hazard warning lamp - 13•4
horn - 13•5
hydraulic pressure (brakes) - 10•17
ignition/lockbarrel - 13•4
luggage area light - 13•5
oil pressure warning - 13•6
reversing - 7B•6, 13•4
starter inhibitor - 7B•6
TTachometer- 13•8
Tailboard- 12•11
Tailgate struts- 12•6
Tailgate/lock- 12•5, 12•6
Temperature gauge and sender unit- 3•8
Thermostat- 3•4
Throttle body- 4B•12
Throttle cable- 4A•8
Throttle position sensor- 4B•11
Throttle valve control motor- 4B•11Tie-rod end- 11•18
Timing adjustment- 5•17
Timing belt/chain and sprockets- 2A•12,
2B•8, 2C•10
Tools and working facilities- REF•5
Towing- 0•7
Transmission housing oil seal- 7B•5
Trim panel (door)- 12•7
Tyre checks and pressures- 0•16, 0•18
UUnderbody- 1•7 1•8, 1•17, 12•2
Underbonnet views -0•10, 1•5
Unleaded petrol- 5•18
Upholstery and carpets- 12•2
VVacuum diaphragm unit- 7B•6
Vacuum servo unit (braking system)- 10•14
Valve block (ABS)- 10•17
Valves- 1•15
Vehicle identification numbers- REF•3
Ventilation system- 3•1 et seq
WWarning system components- 13•9
Washer fluid level- 0•13
Washers- 13•12
Weatherstrip- 12•15
Weber 2V carburettor- 1•12, 4A•14
Weber 2V TLD carburettor- 1•12, 4A•15
Weekly checks- 0•10
Wheel (steering) - 11•14
Wheel alignment- 11•1, 11•19
Wheel arch liners- 12•14
Wheel bearings- 11•6, 11•10
Wheel changing- 0•6
Wheel cylinder- 10•12
Wheel sensor(ABS)- 10•18
Window glass- 12•11
Window regulator- 12•12
Windscreen- 12•11, 12•14
Windscreen washers- 13•12
Windscreen wiper motor- 13•12
Wiper arms- 13•11
Wiper blades- 0•15, 13•11
Wiper motor (headlamp)- 13•13
Wiper motor (rear)- 13•12
Wiper motor (windscreen)- 13•12
Wiring diagrams- WD•1 et seq
Working facilities- REF•5
IndexREF•25
REF