Vauxhall ASTRA Owner's Manual page 142

9.3 Undo the screws and lift away the
plastic cover
9 Alternator -
brush renewal
1 Remove the alternator, as described in
Section 8.
2 Place the alternator on a clean work
5urface, with the pulley facing down .
3 Undo the retaining screws, and lift away the
J4Jter plastic cover (see illustration). .
4 Unscrew the two retaining screws and ease
"'le
wire from the connector (see illustrations) .
5
If the brushes are damaged or excessively
",orn, the brush pack must be renewed.
6
Clean and inspect the surfaces of the slip
ngs, at the end of the alternator shaft. If they
u e excessively worn, or damaged, the
ltternator must be renewed.
Reassemble the alternator by following the
;;.smantling procedure in reverse, taking care
Cl
ease the brushes over the end of the slip
ngs (see illustration). On completion , refer
:) Section 8 and refit the alternator.
10 Starting system -
testing
~ote:
Refer to the precautions given in 'Safety
'S t!' and in Section
1
of this Chapter before
; !arting work.
If the starter motor fails to operate when the
;jnition key is turned to the appropriate
Xl sition, the following possible causes may
--e to blame.
a) The battery is faulty.
0)
The electrical connections between the
switch, solenoid, battery and starter
motor are somewhere failing to pass the
necessary current from the battery
. through the starter to earth.
~)
The solenoid is faulty.
d)
The starter motor is mechanically or
electrically defective.
2 To check the battery, switch on the
- eadlights. If they dim after a few seconds,
"'us indicates that the battery is discharged -
'i!Charge (see Section 3) or renew the battery.
• the headlights glow brightly, operate the
~ ition switch and observe the lights. If they
Starting and charging
syst~ms
SA.S
9.4a Unscrew the brush pack screws ...
dim, then this indicates that current is
reaching the starter motor, therefore the fault
must lie in the starter motor. If the lights
continue to glow brightly (and no clicking
sound can be heard from the starter motor
solenoid), this indicates that there is a fault in
the circuit
or
solenoid - see following
paragraphs. If the starter motor turns slowly
when operated, but the battery is in good
condition, then this indicates that either the
starter motor is faulty, or there is considerable
resistance somewhere in the circuit.
3 If a fault in the circuit is suspected,
disconnect the battery leads (including the
earth connection to the body), the starter/
solenoid wiring and the engine/transmission
earth strap. Thoroughly clean the
connections , and, reconnect the leads and
wiring, then use a voltmeter or test lamp to
check that full battery voltage is available at
the battery positive lead connection to the
solenoid, and that the earth is sound. Smear
petroleum jelly around the battery terminals to
prevent corrosion - corroded connections are
amongst the most frequent causes of
electrical system faults.
4 If the battery and all connections are in
good condition, check the circuit by
disconnecting the wire from the solenoid
blade terminal. Connect a voltmeter or test
lamp between the wire end and a good earth
(such as the battery negative terminal) , and
check that the wire is live when the ignition
switch is turned to the 'start' position. If it is,
then the circuit is sound - if not the circuit
wiring can be checked as described in
Chapter '12, Section 2.
9.7 Compress the brushes and refit the
brush pack
9.4b '" and ease the connector apart
5 The solenoid contacts can be checked by
connecting a voltmeter or test lamp between
the battery positive feed connection on the
starter side of the solenoid, and earth. When
the ignition switch is turned to the 'start'
position, there should be a reading or lighted
bulb, as applicable.
'if
there is no reading or .
lighted bulb, the solenoid is faulty and should
be renewed.
6 If the circuit and solenoid are proved
sound, the fault must lie in the starter motor.
In this event, it may be possible to have the
starter motor overhauled by a specialist, but
check on the cost of spares before
proceeding, as it may prove more economical
to obtain a new or exchange motor.
11 Starter motor -
removal and refitting
Removal
1 Disconnect the battery negative lead, then
firmly apply the handbrake then jack up the
front of the vehicle and support it on axle
stands. Where necessary, undo the retaining
bolts and remove the undercover from
beneath the engine/transmission unit.
Proceed as described under the relevant sub-
heading . Note: Before disconnecting the
battery, refer to 'Disconnecting the battery' in
the Reference section at the rear of this
manual.
SOHC engine
2 Slacken and remove the two retaining nuts
and disconnect the wiring from the starter
motor solenoid . Recover the washers under
the nuts.
3 Unscrew the retaining nut and disconnect
the earth lead from the starter motor upper
bolt. .
4 Slacken and remove the retaining bolt and
nut, then manoeuvre the starter motor out
from underneath the engine.
DOHC engines
5 Undo the retaining bolts and remove the
support bracket from the underside of the
inlet manifold.
SA