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ELECTRICAL SYSTEMS
BATTERY
10-17
connected in series with the
ammeter.
This test
may be made with battery either installed or
removed, and without cranking the engine.
1. Adjust rheostat to
provide maximum
resistance (OFF position).
2. Connect ammeter positive
(+)
lead to
battery positive
(
+)
post, and negative (-)
lead to one side of rheostat. Connect other side
of rheostat to battery negative (-) post. In
the instrument shown in figure 10-5 the
am-
meter and rheostat are connected in series in-
side the case. If battery is installed, connect
ammeter and rheostat leads to battery cable
terminals so that battery posts are not covered.
3.
Attach prods to voltmeter leads using
care to obtain clean metal contact between
prods and clips on leads. Apply prod of positive
(
+
)
lead to
center
of positive battery post and
apply prod of negative (-) lead to
center
of
negative (-) battery post. CAUTION:
Do not
apply voltmeter leads to cable terminals as any
resistance in the connection between terminals
and battery posts will affect the test
readings.
4. Adjust rheostat until ammeter reads 300
amperes, immediately read voltmeter, then re-
turn rheostat to starting position to avoid ex-
cessive drain on
battery.
5. Voltmeter will read 4 or more volts if
battery discharge capacity is
satisfactory.
If
voltmeter reads less than 4 volts, the battery
must be completely recharged and tested again.
b.
High Discharge Test With Voltmeter,
While Cranking Engine
If
equipment specified above is not available,
the battery may be given a high discharge test
Figure 10-6-High Discharge Test of Battery Cell with Voltmeter
by using a low-reading voltmeter while crank-
ing the
engine.
The voltmeter leads must be
provided with long sharp prods so they can be
pressed through sealing compound to contact
the cell terminal posts.
When
making this
test
the engine must
be
at
normal
operating temperature
to insure normal
cranking load.
1. Ground the primary terminal of distrib-
utor with a jumper wire so that engine can be
cranked without
firing.
2. Connect voltmeter leads to the terminals
of each battery cell in turn and quickly note the
voltmeter reading while cranking the engine.
See figure 10-6. Do not operate cranking motor
more than thirty seconds at any time without
pausing for a few minutes to allow it to cool;
otherwise,
cranking motor may be severely
damaged.
3. Remove jumper wire from distributor
as soon as test is finished
.
4. If the voltage of any cell falls below 11j2
volts, or if there is a difference of more than
0/10
volt between cells, the battery should be
removed and fully
recharged,
then give another
high discharge test to determine whether re-
placement is necessary.
10-21 TESTING AND CLEANING
BATTERY CABLES AND
CONNECTIONS
Whenever the battery is tested
(par.
10-20)
the battery cables should also be inspected for
condition and tested for
resistance.
Resistance
in the battery cables and
connections
causes
voltage drop, and excessive voltage drop is
liable to cause starting difficulties.
a. Inspection of Cables and Terminals
Inspect battery cables for broken insulation,
corroded or broken
strands,
or looseness in ter-
minals.
Repair
broken insulation with loom or
tape;
however,
if
cable
strands are broken, cor-
roded
,
or
loose
in t
erminals
the cable should be
replaced with a genuine Buick cable to insure
ample capacity.
Check terminals at both ends for tight con-
nections. Since loose connections are usually
dirty or corroded, any loose connections should
be thoroughly cleaned before being tightened.
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