Nissan PULSAR N13 Series / ASTRA LD Series. Manual - 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