Ford Granada 1985-1994, Руководство пользователя

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The electrical system is a 12 volt, negative
earth type. Electricity is generated by an
alternator, belt-driven from the crankshaft pulley.
A lead-acid battery provides a reserve of power
for starting and when the demands of the system
temporarily exceed the alternator output.
The battery negative terminal is connected
to “earth” - vehicle metal - and most electrical
system components are wired so that they
only receive a positive feed, the current
returning via vehicle metal. This means that
the component mounting forms part of the
circuit. Loose or corroded mountings can
therefore cause apparent electrical faults.
Many semiconductor devices are used in
the electrical system, both in the “black
boxes” which control vehicle functions and in
other components. Semiconductors are very
sensitive to excessive (or wrong polarity)
voltage, and to extremes of heat. Observe the
appropriate precautions to avoid damage.
Although some repair procedures are given
in this Chapter, sometimes renewal of a well-
used item will prove more satisfactory. The
reader whose interests extend beyond
component renewal should obtain a copy of
the “Automobile Electrical Manual”, available
from the publishers of this book.
Before starting work on the electrical
system, read the precautions listed in “Safety
first!” at the beginning of the manual.
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
anti-lock braking systems), particularly where an
electronic control unit (ECU) is involved.
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
Chapter.
2 Before attempting to diagnose an electrical
fault, first study the appropriate wiring
diagram, to obtain a more complete
understanding of the components included in
the particular circuit concerned. The possible
sources of a fault can be narrowed down by
noting whether 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. 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), a self-powered test
light (sometimes known as a continuity tester),
an ohmmeter (to measure resistance), 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), an integrity test
can be performed on the wiring, which
involves moving 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, but will
not cause the relevant circuit fuse to blow.
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. Note: A short-
circuit that occurs in the wiring between a
circuit’s battery supply and its fuse will not
cause the fuse in that particular circuit to blow.
This part of the circuit is unprotected - bear
this in mind when fault-finding on the vehicle’s
electrical system.
Finding an open-circuit
9 To check for an open-circuit, connect one
lead of a circuit tester or voltmeter to either the
negative battery terminal or a known good earth.
10 Connect the other lead to a connector in
the circuit being tested, preferably nearest to
the battery or fuse.
11 Switch on the circuit, bearing in mind that
some circuits are live only when the ignition
switch is moved to a particular position.
12 If voltage is present (indicated either by
the tester bulb lighting or a voltmeter reading,
as applicable), this means that the section of
2 Electrical fault-finding - general
information
1 General information
Body electrical system 13•3
13
Other relays and modules (continued)
Identification Function
Behind facia (passenger side) (continued):
M4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Heated windscreen (timer)
M5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Air conditioning cooling fan
M6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ABS pump relay
M7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ABS main relay
M8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ABS control unit
M9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ride height control
Below instrument panel (driver’s side):
N1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bulb failure warning unit
Below facia (passenger side):
P1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ABS module
P2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fuel-injection system module
Behind facia (passenger side):
R1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Speed control system module
R2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Auxiliary warning system module
R3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rear audio console module
Torque wrench settings
Nm lbf ft
Alternator adjusting strap:
To steering pump bracket (SOHC) . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 to 26 16 to 19
To front cover (V6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 to 51 30 to 38