If
reading
obtained
is stable
but
outside the
appropriate
limits
the
unit can be adjusted as follows.
ADJUSTMENT
OF VOLTAGE SETTING
Stop
the
engine
and
remove the
control
unit from its
mounting.
At
the
back
of the unit is a sealed potentio-
meter
adjuster.
Carefully
scrape away the sealing com-
pound. Then start
the
engine, and
while
running the
alternator
at
charging
speed, turn the
adjuster
slot
-
CLOCKWISE to INCREASE the setting or ANTI-
CLOCKWISE to DECREASE it - until the required set-
ting
is obtained.
Recheck
the
setting
by stopping the engine, then
start
again
and slowly
"run-up"
to
charging
speed.
If
set-
ting
is
now
correct,
remount the
control
unit, dis-
connect
test meters and restore
original
wiring
con-
nections.
If,
after
adjustment, the
voltmeter
reading re-
mains
unchanged,
or
increases in an
uncontrolled
manner, then the
control
unit is faulty and a replace-
ment
must be fitted.
TEST 4
Check Alternator Output
Disconnect
battery earth cable,
and
connect
test
ammeter
between the
alternator
main terminal and
disconnected
cables. Reconnect battery earth cable,
and
switch
on the
vehicles
full
electrical
load and
leave
on
for
3
or
4 minutes. Leave load on and
start
engine
and
run
at
approximately
2000
rev/min.
The
alternator
output
should
balance
the load, and at the
same time
show
a
charge
to the battery.
Check
Warning
Ught
Control
If
warning
light
does
not
function
either
by remaining
"on"
or
"off",
but
the system is
charging
satisfactorily,
connect
voltmeter
between the
alternator
"AL"
terminal
and
earth. Reading
should
be
7.0-7.5
max (12
volt
alternator)
or
14.0-15.0
(24
volt
alternator).
Con-
nect
leads 'E'
and
'WL' together.
If
warning
lamp
lights
the
warning
light
control
is faulty
and
should
be re-
placed.
5.
faun
Diagnosis
Procedure
for
11
AC
Alternator Fails to Charge
(a)
Check
driving
belt
for
correct
tension
and wear.
(b)
Apply
Tests 1
and
2.
ELECTRICAL EQUIPMENT
-Q.3
Low-Unsteady Charging Rate
(a)
Check
driving belt
for
correct
tension
and
wear.
(b)
Check
for
high
resistance
at
battery
terminals
and in the
circuit
wiring
and
connection.
(c)
Check
all
connections
made
to
earth.
(d)
Apply
Test
2.
Flat Battery or Low State
01
Charge
(a)
CHECK
condition
of
battery
with
hydrometer
and
high rate
discharge
tester.
(b)
Check
driving
belt
for
correct
tension
and
wear.
(c)
Check
that the field
isolating
relay
contacts
open
when
master
switch
is off,
otherwise
battery
will
discharge
through
rotor
winding.
(d)
Check
that flat
or
low
battery
is
not
caused
by
insufficient
alternator
output
caused by
abnormal
electrical
loads
by
applying
Test
4.
Excessive Charge Rate
to
a Fully Charged Battery
(a)
Apply
Test
3.
Noisy Alternator
(a)
Alternator
loose
in
mounting
brackets.
(b)
Worn
frayed
or
loose
drive
belt.
(c)
Worn
bearings,
fully
out
of
alignment.
(d)
Rotor
damage
or
pulley
fan loose on shaft.
(e)
Open
circuited,
or
short
circuited
rectified
diodes,
or
stator
winding
open-circuit.
(f)
Loose
pulley.
6.
Testing
the
15ACR and 17ACR
Alternator
in
Position
First
check
the
driving
belt
for
condition
and tension.
The
nominal
hot
outputs
at
6,000
rev/min
(alternator
speed)
are
28
amps
and
36 amps
for
15ACR and
17
ACR
alternator
respectively.
These figures may be
exceeded
slightly
when
the
alternator
is running cold.
To
avoid
misleading
results,
the
following
test pro-
cedure
should
therefore
be
carried
out
with
the alter-
nator
running
as
near
as
possible
to
its
normal
opera-
ting
temperature.
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