Nissan PULSAR N13 Series / ASTRA LD Series. Instruction — part 49

Electrical System

197

Switch on all lamps and allow them to

illuminate for approximately five minutes to reduce
the charge of the battery and to apply a load to the
circuit.

Start the engine and gradually increase the

speed to approximately 2 500 rpm. The reading on
the ammeter should be approximately 75% of the
rated output of the alternator. See Specifications.

Switch off all the lamps and run the engine at

1 500-2 000 rpm until the indicated charge is below
10 amps. The voltmeter should now read in excess of
13.6 volts.

NOTE: Should the alternator fail to reach
the specific output, the unit will have to be
removed and overhauled or a replacement
unit installed.

Should the voltage reading be above or

below Specifications, the regulator will have
to be renewed.

TO REMOVE AND INSTAL

Disconnect the negative battery terminal.

On 1.8 liter engines, remove the bolt secur-

ing the air cleaner intake duct and remove the air
cleaner intake duct.

Drain the radiator by releasing the radiator

drain plug, located at the bottom of the radiator and
allow the coolant level to fall below the thermostat
housing level.

NOTE: Refer to the Cooling and Heating
Systems section when refilling the radiator
coolant to its correct level, failure to do so
could result in severe damage to engine
components.

Remove the retaining bolts securing the

thermostat housing, disconnect the hose from the
radiator and remove the thermostat housing and
radiator hose from the vehicle.

Using a socket and extension bar, remove the

bolt securing the alternator to the drive belt tensioning
bar located under the alternator.

On vehicles not equipped with air condition-

ing, remove the front splash guard from under the
front of the vehicle and remove the bolt securing the
alternator to the drive belt tensioning bar.

Loosen the upper mounting bolts, slacken

the alternator drive belt and remove it from the
alternator pulley.

While supporting the alternator, remove the

upper mounting bolts and remove the alternator from
the vehicle.

Installation is a reversal of the removal procedure

with attention to the following points:

Do not over tension the drive belt. Refer

to
the Engine Tune-up section for the correct belt
adjusting procedure.

Ensure that the wiring and connectors are

securely located on the alternator.

Dismantled view of the Bosch alternator.

198

Electrical System

(3) Replenish the coolant in the radiator. Refer

to the Cooling and Heating Systems section for the
correct procedure.

TO DISMANTLE

Bosch Alternator

Remove the alternator from the vehicle as

previously described.

Scribe a mark across the drive end bracket,

stator and slip ring end bracket to facilitate correct
alignment during assembly.

Remove the screws and washers securing the

regulator and brush holder assembly. Withdraw the
regulator and brush holder assembly from the alter-
nator.

Remove the long screws securing the drive

end bracket to the slip ring end bracket and withdraw
the drive end bracket, rotor and pulley assembly.

NOTE: Ensure that the wave washer behind
the rotor shaft rear bearing in the slip ring
end bracket is not mislaid.

Holding the rotor in a soft jawed vice,

remove the split drive pulley retaining nut, washer
and spacer from the rotor shaft.

Remove the split drive pulley, spacer, plate

washer and fan from the rotor shaft.

Using a suitable press and press plates,

support the drive end bracket with the pulley end of
the rotor shaft uppermost and carefully press the rotor
shaft from the spacer, bearing and the drive end
bracket.

Remove the spacer and the bearing retainer

plate screws from the drive end bracket.

Remove the bearing retainer plate and the

bearing from the drive end bracket.

If necessary, using a bearing puller, remove

the rear bearing from the rotor shaft.

Remove the nut, spring washer and output

terminal components from the {B + ) terminal on the
outside of the slip ring end bracket.

(12) Working inside the slip ring end bracket,

remove the screws securing the diode pack to the
bracket and withdraw the stator and diode pack as an
assembly. Remove the insulating spacer and washer
from the (B +) terminal.

NOTE: The diode pack is supplied as an
assembly and in the event of a component
'failure, must be renewed as a complete unit.

Mark all wiring connections prior to removal

to aid assembly.

Where necessary, unsolder the stator leads

from the connector terminals to separate the diode
pack.

NOTE: When soldering or unsoldering the
stator leads from the diodes, grip the leads
with a pair of long nosed pliers. This will
safeguard the diodes by transferring any
excess heat to the jaws of the pliers.

Hitachi Alternator

Remove the alternator from the vehicle as

previously described.

Scribe a mark across the drive end bracket,

stator and slip ring end bracket to facilitate correct
alignment during assembly.

Remove the through bolts retaining the drive

end bracket to the slip ring end bracket.

Apply a heated 200 watt soldering iron to the

slip ring end bracket at the bearing mounting boss for
3-4 minutes to heat the bracket and allow the removal
of the slip ring end bearing.

Carefully prise the slip ring end bracket and

stator assembly from the drive end bracket and rotor
assembly using suitable levers. Do not insert the levers
too far or damage to the stator will occur.

Hold the rotor and drive end bracket assem-

bly in a soft jawed vice and remove the nut retaining
the drive pulley to the rotor.

Remove the washer, pulley and spacer

washer from the rotor shaft.

Using a soft faced hammer, drive the rotor

shaft assembly from the drive end bracket and remove
the inner spacer washer from the rotor shaft.

Remove the bearing retainer plate screws

and remove the plate. Using a suitable drift, drive the
bearing from the bracket.

Remove the retaining nut and insulator

washer from the alternator terminal.

Remove the slip ring end bracket retaining

nuts and separate the diode pack, stator and regulator
assembly.

If necessary, file the ends of the brush

assembly retaining rivets, carefully unsolder the ter-
minal plate and remove the brush assembly and
terminal plate from the diode pack.

If necessary, remove the fan guide retaining

View of the Bosch alternator stator assembly and the

slip ring end bracket.

Electrical System

199

Dismantled view of the Hitachi alternator.

nuts, remove the fan guide and unsolder the diode
pack and regulator from the stator.

NOTE: When soldering or unsoldering the
stator leads or bridges from the diodes or
regulator, grip the leads with a pair of long
nosed pliers. This will safeguard the diodes
by transferring any excess heat to the jaws of
the pliers.

TO CLEAN PARTS

Do not immerse components of the alterna-

tor in cleaning solvents as damage to the windings will
result.

Thoroughly clean and dry the end brackets in

a suitable solvent after they have been completely
dismantled from the unit.

Compressed air can be carefully used to blow

the dust from the stator windings and the field
winding on the rotor.

Slip rings that are burned or scored should be

polished using very fine glass paper.

Clean the brushes and the brush holders

using a petrol dampened rag. Check and remove any
burrs from the holder.

Check the rotor shaft bearings for wear and

roughness and renew as necessary.

TO CHECK AND TEST COMPONENT
PARTS

All parts being electrically tested should be resting

on a non-conductive pad.

Field Windings and Rotor Assembly

The insulation to earth test is done with an

ohmmeter. Connect one of the test prods to one of the
field wires or slip rings and the other test prod to one
pole piece of the rotor.

If the ohmmeter shows a reading and no

visual earthing can be seen and rectified, a new rotor
assembly will have to be installed.

To check for bridged or internal shorting of

the field coils, connect the test prods of an ohmmeter
across the slip rings and check the resistance of the
rotor windings. Compare the readings with Specifica-
tions. A low reading indicates a bridged circuit

OHMMETER

Checking the rotor windings for shorts to earth.

200

Electrical System

Using an ohmmeter to test for bridging or internal

shorting of the rotor fields.

internally, while a high reading indicates an open
circuit or high resistance in the windings. In both
cases a new rotor assembly will have to be installed.

Stator Windings

The stator test is carried out using a test lamp.

The stator leads must be detached from the

diode pack.

Connect a jumper lead from the negative

terminal of a charged 12 volt battery to the stator
winding frame. Connect one end of a test lamp to the
battery positive terminal, the other end of the test
lamp to the stator lead, one at a time.

Should the test lamp illuminate, however

dimly, a short circuit is indicated and the stator
assembly must be renewed.

Diodes

On some models the diodes may be tested after

disconnection. Testing can be done by using a 12 volt
battery and a 1.5 watt bulb in series with a jumper
lead.

Connect a jumper lead from the negative

terminal of a charged battery to the carrier/bracket
holding the diode to be tested.

Connect one end of a test lamp to the battery

positive terminal and the other end of the lamp to the
diode lead. Note whether the lamp is illuminated and
then reverse the connections on the battery.

If the lamp was illuminated in both direc-

tions or was not illuminated at all, the diode is faulty
and the diode pack/heat sink must be renewed.

Brush Springs and Brushes

Check the brush springs for overheating and

distortion, check for binding in the brush holder.

Check the brush length and renew as neces-

sary. Refer to Specifications for the correct dimen-
sions.

TO ASSEMBLE

Bosch Alternator

Assembly is a reversal of the dismantling proce-

dure with attention to the following points:

Using a hot soldering iron and a pair of long

nosed pliers as a heat sink, solder the stator leads to
their respective terminals on the diode pack.

Install the insulating washer and spacer to the

(B +) terminal post and position the diode pack and
stator assembly onto the slip ring end bracket. Install
the diode pack retaining screws and tighten securely.

Working on the exterior of the slip ring end

bracket, install the output terminal components to
the
(B + ) terminal and secure the retaining nut.

Position the bearing retainer, bearing and

spacer on the rotor shaft.

Using a suitable press and press plates,

support the rotor shaft on the front face of the spacer
and carefully press the rotor shaft fully into the
bearing and spacer.

Position the rotor shaft assembly into the

rear of the drive end bracket and install and tighten the
bearing retainer plate screws.

Install the fan, plate, spacer and split

drive
pulley to the rotor shaft and secure them with the
retaining washer and nut.

If necessary, using a suitable press and press

plates, support the rotor shaft rear bearing and
carefully press the rotor shaft fully into the bearing.

NOTE: Ensure that pressure is applied only
to the inner race of the bearing.

Ensure that the rotor shaft bearing wave

washer is located in the slip ring end bracket and
insert the rotor in the stator and slip ring end bracket
assembly.

Align the marks made on dismantling and

install and tighten the long securing screws.

Position the regulator and brush holder as-

sembly to the slip ring end bracket and install
and
tighten the retaining screws.

Install the alternator to the vehicle and

test
the operation as previously described.

Hitachi Alternator

If necessary, position the new brush termi-

nals in the brush assembly and install the
brush
assembly and terminal plate to the diode pack.
Carefully solder the terminal plate to the diode pack
and secure the brush assembly by installing and
staking new rivets.

If necessary, solder the diode pack and

regulator to the stator and install the fan guide
and
retaining nuts. Tighten the retaining nuts securely.

NOTE: When soldering or unsoldering the
stator leads or bridges from the diodes or
regulator, grip the leads with a pair of long