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 en d 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 diod es 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 spring s 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 sh aft 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 prev iously 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
