Rolls-Royce Silver Shadow
B
Bentley
T
Series
Workshop
Manual
3.
Close switch
4
and observe that the bulb is lit.
4.
Start the dl~ve and increase speed until
warning lamp is extinguished which indicates that
alternator is charging. This should occur below
2000
r.p.m.
5.
Reduce alternator speed to
1125
r.p.rn. and
measure dc voltage between WL and -ve on the
440 regulator. The voltage should be between
12-14 volt.
Load Ammeter Voltage
applied reading
40-50 amp 50-55 amp
@
13-1 3.6
6.
Increase alternator speed to 10,000
r.p.m. and
again observe ammeter reading which should be as
follows:
-
Ammeter Voltage
reading
60-65 amp
@
13-14
Adjust battery load as necessary. Run at top speed
of 10,000 r.p.m. for 1 minute.
7.
Decrease speed to 3000
r.p.m. and switch off
loads connected across the battery, the voltage
should rise to between 13-14 volts and then remain
constant. At the same time
the current reading
should drop appreciably. This test indicates that
the regulator is working correctly.
With switches
8
and
9
open, the voltmeter reading
should be between 14 and 14.5 volts. With
8
closed
and
9
open the voltmeter reading should be between
13.5 and 14 volts and with both
8
and
9
closed the
voltmeter reading should be between 13 and
t3.5
volts.
Alternator
Lucas Model
20
ACR
Important
Before commencing work on the
alternator, please note the
following:
1.
If it is necessary to disconnect a lead from
the system, the engine must be switched off.
2.
Whenever a lead is disconnected it should be
identified in relation to its terminal to facilitate
reconnection. Short circuiting or reverse polarity
no matter how brief will cause immediate and
permanent damage to transistors and diodes.
3.
The battery must not be disconnected whilst
the alternator is running nor should the battery be
connected into the system without first checking
for correct polarity.
4.
Do not use insulation testers on the alternator
Chapter
M
Routine maintenance
a. Cleaning
Wipe away any dirt or oil that has collected
around the apertures in the moulded cover.
b. Belt adjustment
Inspect the driving belt for condition and correct
tension. If necessary adjust the tension so that
an applied force of 3,6 kg.
(8
lb.) mid-way
between the two pulleys causes the belt to
deflect 9,5 mm. (0.375 in.).
lmportant
To avoid damage to the alternator
when adjusting belt tension, apply
leverage only on the alternator
drive end bracket, not on any other
part of
the
alternator. The lever
should be of a soft material,
preferably wood.
c. Lubrication
The bearings are packed with grease during
assembly and will not normally require further
lubrication during their service life.
d. Circuit connections
Ensure that parts of the charging circuit,
including the battery, are not disconnected or
connected while the engine is running. When
connecting an alternator, always observe
correct polarity
i.e. positive to positive and
negative to negative.
Alternator-To service in position
Alternator output test
This test should be carried out with the alternator
at
normzl temperature. Run a cold engine at
charging speed for
3-4 minutes.
a. With the engine stationary, disconnect the
battery earth cable.
b. Connect an ammeter in series with the alternator
main output cable.
c. Remove the connections from the alternator,
remove the moulded cover and remake the connec-
tions. Short together the black lead and the large
'
Philips' screw securing the metal plate.
d. Connect the battery earth cable.
e. Switch on all the vehicle loads (except wipers)
and switch on the ignition. Observe that the
warning lamp is illuminated.
f.
Start the engine and slowly increase the speed.
At
3000 r.p.m. the ammeter reading should be
66 amps. Any appreciable deviation from this
figure will necessitate removal of the alternator
for further examination.
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