alternator belt NISSAN PULSAR 1987 User Guide

196 Electrical System



Check the specific gravity in each cell with a hydro-
meter.
Check the battery electrolyte level and re-
plenish as necessary. Remove the filler cap s from the battery.
Follow the battery charger manufacturers
instructions. (3) Should the battery fail to operate satisfacto-
rily after charging, it is recommended that it be taken
to a workshop with the necessary equipment to per-
form a load test. Load testing, when performed in
conjunction with the specific gravity tests described
above will give an accurate indication of the service-
ability of the battery.
7. ALTERNATOR
Special Equipment Required
To Test On Vehicle - Voltmeter, 100-0-100
amp ammeter, ohmmeter
To Dismantle — 200 watt soldering iron,
bearing
puller, press
To Assemble — 200 watt soldering iron
DESCRIPTION
Two types of alternator are installed to the range
of vehicles covered by this manual, either Hitachi or
Bosch. In the alternator, the field and pole shoe assembly
is the moving part and it is shaped to form the rotor.
Since only a low amperage current flows between the
slip rings on the rotor shaft and the brushes, wear on
the brushes and slip rings is very slight and mainte-
nance is reduced to a minimum. The output current is generated in the fixed stator
windings and is a three phase alternating current
(AC). The stator windings are wound on a laminated
soft iron former, star connected and installed between
the end brackets. As it is not possible to charge a storage battery
with alternating current, it is necessary to rectify the
output of the stator windings to direct current (DC). This is done by a bank of diodes mounted within the
alternator slip ring end bracket.
The output of the alternator is governed by the
regulator and the built in ch aracteristics of the alter-
nator.
The regulator and brush holder assembly on
Hitachi alternators is mounted within the alternator
on the slip ring end bracket side. On Bosch
alternators
the regulator and brush holder unit is mounted to the
outside of the slip ring end bracket. An electrical cut out unit is not necessary with the
alternator charging system as the diodes prevent a
reverse current flow through the alternator.
SERVICE PRECAUTIONS
Ensure that the battery is connected with the
correct polarity to earth. Refer to Specifications.
Do not short out or ground any terminals
common to the charging circuit. Always disconnect the battery before con-
necting a battery charger.
If a booster battery is used, always connect it
in a parallel circuit i.e. positive to positive ( + to + )
and negative to negative (- to -) to maintain a 12
volt supply. Never disconnect the battery or terminals in
the charging circuit while the engine is running. Regularly check that the alternator drive belt
tension is as specified. Refer to the Engine Tune-up
section.
Keep the battery terminals clean and all
electrical connections tight. Disconnect the battery and alternator when
electric welding on the vehicle.
TO TEST ON VEHICLE If the charge indicator lamp stays on after the
engine has been started and run at approximately
1 000 rpm, carry out the following tests. Stop the engine.
Check the condition and adjustment of the
alternator drive belt. Clean the battery terminals, tighten all elec-
trical connections, check the wiring for shorts to earth
and/or bridged circuits. Ensure that the battery is fully
charged. If the battery is discharged charge it or
replace it with one fully charged. Start the engine and allow it to run until
normal operating temperature is reached.
Stop the engine and disconnect the negative
battery terminal.
Remove the nut and washer from the alter-
nator output terminal (B +) and disconnect the alter-
nator output lead. Connect one lead of an ammeter to the
alternator output terminal and the other lead to the
lead removed from the output terminal. Connect the negative battery terminal and
connect a voltmeter across the battery terminals.

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 altern ator. 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 l
evel, 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.