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ELECTRICAL SYSTEM
The starting system uses a 6 volt starter mot or
and left hand inboard type Bendix drive, on cars
not equipped with Hydra-Matic Drive, and a right
hand outboard Bendix Drive with cars equipped
with Hydra-Matic Drive. The starter motor is
energized by the battery through a solenoid.
Turning ignition sw itch key to the extreme right
activates the solenoid.
BATTERY
The battery used i s a National, Model 1W-90,
45 plate 6 volts 90 ampere hour storage battery.
Electrolyte level should be at the bottom of the
square in filler cap opening. Use distilled water in
the battery. Level should be checked at lubrica-
tion periods and more often in warm weather.
Battery terminals should be kept clean and tight
at all times.
BATTERY TEST
HYDROMETER
Under normal conditions a hydrometer reading of
the specific gravity of each cell will determine the
state of charge. A specific gravity of 1270 at 70° F
indicates a fully charged battery. A specific gravity of
1.130 indicates a fully discharged battery. If specific
gravity varies more than 25 points between cells,
recharge and retest or test under load.
VOLTMETER
A battery that fails to perform properly after
charging should be tested with a volt-meter. Each
cell should show two volts or over under no load,
and the voltage across the terminal posts should
be six volts or over.
If these readings cannot be obtained the bat-
tery should be replaced.
LOAD TEST
A load test should be made to eliminate possi-
bility of a weak cell. Use Battery-starter tester or
a standard cell tester with a heavy shunt across
the terminals. With the cell tester the difference
between cells should be not more than 1.5 volts,
and each cell should test at least 1.5 volts. With
ELECTRICAL SYSTEM 62
the Battery-Starter Tester, meter should show at
least 4 volts at 300 amperes discharge.
If a tester is not available, a voltmeter may be
connected across the battery terminals while en-
gine is cranked with the starter motor.
Battery is serviceable if the starter cranks the
engine at a good speed for 1/2 minute and the
voltage does not fall below 4-½ volts. DO NOT
CRANK MORE THAN 1/2 MINUTE WITHOUT
ALLOWING THE STARTER MOTOR TO
COOL.
A slow cranking speed or voltage lower than
4-1/2 indicates a weak cell or high resistance in the
connections to the starter, and the battery cables
should be checked and load test repeated.
BATTERY CABLE CHECK
1. Connect a negative voltmeter lead to th e negative
battery terminal and the positive lead to the starter
motor terminal. Crank the motor with the starter.
Voltage should not exceed .2 volts.
2. Connect the positive voltmeter lead to the battery
ground post and connect the negative lead to car
frame. Crank the motor with the starter. Voltage
should not exceed .2 volts.
3. Connect positive voltmeter lead to car frame and
negative lead to starter motor frame. Crank the
motor with the starter. Voltage should not ex-
ceed .2 volts.
4. If voltage loss is greater than above, terminal
posts, ground strap and connections, and starter
solenoid should be checked for high resistance.
CRANKING VOLTAGE TEST
1. Connect the negative voltmeter lead of the
starter motor tester to the starter switch terminal
and the positive lead to the engine for a ground.
2. With the ignition key off, engage the starter
motor and note reading on the voltmeter. The
cranking voltage should read 5 volts or more.
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