ENGINE-ELECTRICAL 6Y-2
PARTITION
PLATE
STRAP
CONNECTOR
Fig.
2b—Internal View of Two Cells Showing Connector
through Partition
DRY CHARGED BATTERIES
A "dry charge" Battery contains fully charged ele-
ments which have been thoroughly washed and dried. Hiis
type of Battery contains no electrolyte until it is activated
for service in the field and, therefore, leaves the factory
in a dry state. Consequently, it is called a "dry-charge"
Battery.
Each vent well in a "dry charge" Battery has an inte-
gral hard rubber seal to prevent the entrance of air and
moisture which would oxidize the negative active mate-
rials and reduce the freshness of the Battery (fig. 3b).
The integral hard rubber seals and the sealing compound
between the case and one-piece cell cover make possible
a. vacuum sealed assembly which can be stored for very
long periods of time without detrimental effects.
Before activating the "dry charge" Battery, the inte-
gral hard rubber seals may be broken simply by pushing
the Delco Eye down into each vent well. The seals drop
into the cells, and can remain there since they are not
chemically active and will cause no harm. (The Delco
Eye is a special type of vent plug that is described in the
section entitled "Periodic Servicing".)
ACTIVATING DRY CHARGED BATTERIES
A "dry charge" Battery is activated by filling each
cell with electrolyte, which is a dilute solution of sulfuric
VENT WELL
SEAL
SPLIT VENT
Fig. 3b—Vent Well Construction Showing Seal
acid having a specific gravity of 1.265 at 80°F. The cells
are properly filled when the electrolyte level reaches
the bottom of the "split vent" at the bottom of the vent
well. The split vent is a visual level fill feature designed
into the cell cover of Delco Batteries (fig. 4b). The elec-
trolyte surface will appear distorted when it contacts the
split vent.
The electrolyte level of each cell should be checked
after filling the Battery initially. If the level has fallen
below the split vent, additional electrolyte should be
added. NEVER APD WATER TO THE ELECTROLYTE
WHEN ACTIVATING BATTERY.
Ir?ong and trouble-free service can be anticipated only
if the Battery is properly activated. Improper activation
results in poor performance and short Battery life.
After electrolyte has been added to a "dry charge"
Battery, it then becomes a wet charged Battery and
should be maintained in the same manner as any other
"wet" Battery.
WET CHARGED BATTERIES
Wet charged Batteries contain fully charged elements
and are filled with electrolyte before being shipped from
the factory.
ELECTROLYTE
LEVEL TOO
LOW
ELECTROLYTE
AT CORRECT
LEVEL
Fig. 4b-View Inside Vent Well Showing Electrolyte
CHEVROLET CHASSIS SERVICE MANUAL
ENGINE-EIECTRICAI 6Y-3
PERIODIC SERVICING
Since the Battery is a perishable item which requires
periodic servicing, a good maintenance program will
insure the longest possible Battery life.
COMMON CAUSES OF FAILURE
If the Battery tests good but fails to perform satis-
factorily in service for no apparent reason, the following
are some of the more important factors that may point to
the cause of the trouble.
1.
Vehicle accessories inadvertently left on overnight to
cause a discharged condition.
2.
Slow speed driving of short duration, to cause an
3.
undercharged condition.
A vehicle
capacity.
electrical load exceeding the generator
4.
Defect in the charging system such as high resist-
ance, slipping fan belt, faulty generator or voltage
regulator.
5. Battery abuse, including failure to keep the Battery
top clean, cable clamps and posts clean and tight,
and improper addition of water to the cells.
LEVEL INDICATOR
The Battery features an electrolyte level indicator,
which is a specially designed vent plug with a transparent
rod extending through the center (fig. 5b). When the elec-
trolyte is at the proper level, the lower tip of the rod is
immersed, and the exposed top of the rod will appear
very dark; when the level falls below the tip of the rod,
the top will glow. ,
The Indicator reveals at a glance if water is needed,
without the necessity of removing the vent plugs (fig. 6b).
The Level Indicator is used in only one cell (second
cell cap from positive Battery post) because when the
electrolyte level is low in one cell, it is normally low in
all cells. Thus when the Indicator shows water is needed,
check the level in all six cells.
An alternate method of checking the electrolyte level is
to remove the vent plug and visually observe the electro-
lyte level in the vent well. The bottom of the vent well
features a split vent which will cause the surface of the
electrolyte to appear distorted when it makes contact.
The electrolyte level is. correct when the distortion first
appears at the bottom of the split vent (fig. 4b).
ELECTROLYTE LEVEL
The electrolyte level in the Battery should be checked
regularly. In hot weather, particularly during trip driv-
ing, checking should be more frequent because of more
rapid loss of water. If the electrolyte level is found to be
low, then colorless, odorless, drinking water should be
added to each cell until the liquid level rises to the split
vent located in the bottom of the vent well. DO NOT
OVERFILL because this will cause loss of electrolyte
resulting in poor performance, short life, and excessive
corrosion.
CAUTION: During service only water should be
added to the Battery, not electrolyte.
The liquid level in the cells should never be allowed to
drop below the top of the plates, as the portion of the
INDICATOR
ELECTROLYTE LEVEL
CORRECT
Fig.
5b—Cut-Away View Showing Electrolyte at Proper Level
with Indicator Having Dark Appearance
plates exposed to air may be permanently damaged with a
resulting loss in performance.
WATER USAGE
Excessive usage of water indicates the Battery is being
overcharged. The most common causes of overcharge
are high Battery operating temperatures, too high a volt-
age regulator setting, poor regulator ground wire con-
nection. Normal Battery water usage is approximately
one to two ounces per month per battery.
INDICATOR
Fig.
6b—Cut-Away View Showing Electrolyte at Low Level
with Indicator Having Light Appearance
CHASSIS SBtVKZ MANUAL
ENGINE-ELECTRICAL
6Y-4
CLEANING
The external condition of the Battery should be checked
periodically for damage or for the presence of dirt and
corrosion. The top of the Battery should be kept clean.
An accumulation of acid film and dirt may permit current
to flow between the terminals, which will slowly dis-
charge the Battery. For best results when cleaning the
top of Batteries, wash first with a diluted ammonia or a
soda solution to neutralize any acid present; then flush
with clean water. Care must be taken to keep vent plugs
tight, so that the neutralizing solution does not enter the
cells.
CABLES
To insure good electrical contact, the cables should be
clean and tight on the Energizer posts. If the posts or
cable terminals are corroded, the cables should be dis-
connected and the terminals and clamps cleaned sepa-
rately with a soda solution and a wire brush. After
cleaning and installing clamps, apply a thin coating of
petroleum jelly on the cable clamps to retard corrosion.
CARRIER
AND
HOLD-DOWN
The Battery carrier and hold-down should be clean and
free from corrosion before installing the Battery. The
carrier should be in a sound mechanical condition so that
it will support the Battery securely and keep it level.
To prevent the Battery from shaking in its carrier,
the hold-down bolts should be tight (60-80 in. lbs.). How-
ever, the bolts should not be tightened to the point where
the Battery case or cover will be placed under a severe
strain.
BATTERY SAFETY PRECAUTIONS
When Batteries are being charged, an explosive gas
mixture forms in each cell. Part of this gas escapes
through the holes in the vent plugs and may form an
explosive atmosphere around the Battery itself if ventila-
tion is poor. This explosive gas may remain in or around
the Battery for several hours after it has been charged.
Sparks or flames can ignite this gas causing an internal
explosion which may shatter the Battery.
The following precautions should be observed to pre-
vent an explosion:
1.
Do not smoke near Batteries being charged or which
have been very recently charged.
2.
Do not break live circuits at the terminals- of Batr
teries because a spark usually occurs at the point
where a live circuit is broken. Care must always be
taken when connecting or disconnecting booster leads
or cable clamps on fast chargers. Poor connections
are a common cause of electrical arcs which cause
BATTERY CHARGING PROCEDURES
There are three methods of recharging Batteries.
They differ basically in the length of time the Battery is
charged and the rate at which charging current is sup-
plied. One is the Slow Charge method, the second is the
Fast Charge method, and the third is the Emergency
Boost Charge method.
Before recharging a Battery by any method, the elec-
trolyte level must be checked and adjusted if necessary.
SLOW CHARGING
The Slow Charge method supplies the Battery with a
relatively low current flow for a relatively long period of
time. This is the only method that will bring the Battery
to a full state of charge.
The Slow Charge method consists of charging at
approximately a 4 ampere rate for 24 hours or more if
necessary to bring the Battery to full charge. A fully
charged condition is reached when the cells are gassing
freely and three corrected specific gravity readings
taken at hourly intervals show no increase.
FAST CHARGING
The Fast Charge method supplies current to the Bat-
tery at a 40 to 50 ampere rate for a 1 1/2 hour period of
time. If the electrolyte temperature reaches 125°F before
the 1 1/2 hour period is completed, the Battery must be
taken off charge temporarily, or the charging rate
reduced to avoid damage to the Battery.
Although a Battery cannot be brought to a fully charged
condition during Fast Charge, it can be substantially
recharged or "boosted". In order to bring the Battery to
a fully charged condition, the charging cycle must be
finished by the Slow Charge method.
EMERGENCY BOOST CHARGING
In cases where the Battery is not sufficiently charged
to crank the engine, an emergency boost charge may be
applied as a temporary expedient in order to crank the
engine. The Emergency Boost Charge method consists of
charging at a 40 to 50 ampere rate for a period of one-
half hour.
It should be particularly noted that the Emergency
Boost Charge will not necessarily restore the Battery to
a useful state of. charge for continued service. After an
emergency boost charge, failure to charge the Battery
further, either by a long uninterrupted driving period or
by the Fast Charge or Slow Charge method, may result
in failure to crank the engine the next time cranking is
attempted. A Battery should never be condemned on the
basis of failure to crank the engine after an emergency
boost charge. Although an emergency boost charge may
put enough energy into the Battery to crank the engine
once, further charging usually is necessary in order to
create a sufficient reserve to crank a second and third
time.
12
VOLT BATTERY SUGGESTED
CHARGING RATES
(100 Amp/hr or Less Capacity)
TYPE OF
CHARGE
Boost Charge for
Light Load Test
Slow Charge
Fast Charge
Quick Boost .
Dry Charge
Warm-up Boost
LENGTH
OF TIME
20 Minutes
24 Hours
1-1/2 Hours
30 Minutes
10 Minutes
CHARGING
RATE
50 Amps
4 Amps
40-50 Amps
40-50 Amps
15 Amps
CHEVROLET CHASSIS SERVICE MANUAL
ENGINE—ELECTRICAL 6Y-5
BATTERY TESTING PROCEDURES
Testing procedures are used to determine whether the
Battery is (1) good and usable, (2) requires recharging or
(3) should be replaced. Analysis of Battery conditions can
be accomplished, by performing a visual inspection,
Instrument Test, and the full charge hydrometer test.
1.
VISUAL INSPECTION
The first step in testing the Battery should be a visual
inspection, which very often will save time and expense
in determining Battery condition.
• Check the outside of the Battery for a broken or
cracked case or a broken or cracked cover. If any
damage is evident, the Battery should be replaced.
« Note the electrolyte level. Levels that are too low or
too high may cause poor performance, as covered in
the section entitled "Periodic Servicing".
o Check for loose cable connections, and for evidence
of corrosion as covered in section entitled ' 'Periodic
Servicing". Correct as required before proceeding
with tests.
2.
INSTRUMENT TEST
A number of suppliers have approved testing equipment
available. These testers have a programmed test proce-
dure consisting of a series of timed discharge and
charge events, requiring approximately 2 to 3 minutes,
that will determine the condition of the Battery with a
high degree of accuracy. When using these testers, the
procedure recommended by the tester manufacturer
should be followed. Batteries should not be charged prior
to testing as doing so may alter the test results. If a
tester is not available for testing, the "Specific Gravity
Cell Comparison Test" may be used or an alternate
method, but with a sacrifice in testing accuracy.
3. FULL CHARGE HYDROMETER TEST
This test should be used only on Batteries which test
good with testing equipment or "Specific Gravity Cell
Comparison Test" but which subsequently fail in service.
• Remove the Battery from the vehicle, and adjust the
electrolyte level as necessary, by adding colorless,
odorless, drinking water.
• Fully charge the Battery at the Slow Charging rate
as covered in the section entitled "Battery Charg-
ing".
• Measure the specific gravity of the electrolyte in
each cell and interpret as follows:
Hydrometer Reading Less Than
1.230—Full
charge
hydrometer readings less than 1.230 corrected for
temperature indicate the Battery is defective and
should be replaced.
Hydrometer Readings Above
1.310—Full
charge hy-
drometer readings above 1.310 corrected for tem-
perature indicate that the cells have been improperly
filled (activation) or improperly serviced. Poor
service and short Battery life will result.
SPECIFIC GRAVITY READINGS
A hydrometer can be used to measure the specific
gravity of the electrolyte in each cell.
The hydrometer measures the percentage of sulphuric
acid in the battery electrolyte in terms of specific
gravity. As a battery drops from a charged to a dis-
charged condition, the acid leaves the solution and enters
the plates, causing a decrease in specific gravity of
electrolyte. An indication of the concentration of the
electrolyte is obtained with a hydrometer.
When using a hydrometer, observe the following points:
1.
Hydrometer must be clean, inside and out, to insure
an accurate reading.
2.
Hydrometer readings must never be taken immedi-
ately after water has been added. The water must be
thoroughly mixed with the electrolyte by charging for
at least 15 minutes at a rate high enough to cause
vigorous gassing.
3.
If hydrometer has built-in thermometer, draw liquid
into it several times to insure correct temperature
before taking reading.
4.
Hold hydrometer vertically and draw in just enough
liquid from battery cell so that float is free floating.
Hold hydrometer at eye level so that float is vertical
and free of outer tube, then take reading at surface of
liquid. Disregard the curvature where the liquid
rises against float stem due to surface tension.
5.
Avoid dropping battery fluid on car or clothing as it
is extremely corrosive. Any fluid that drops should
be washed off immediately with baking soda solution.
The specific gravity of the electrolyte varies not only
with the percentage of acid in the liquid but also with
temperature. As temperature increases, the electrolyte
expands so that the specific gravity is reduced. As
temperature drops, the electrolyte contracts so that the
specific gravity increases. Unless these variations in
specific gravity are taken into account, the specific
gravity obtained by the hydrometer may not give a true
indication of the concentration of acid in the electrolyte.
A fully charged Battery will have a specific gravity
reading of approximately 1.270 at an electrolyte temper-
ature of 80°F. If the electrolyte temperature is above or
below 80°F, additions or subtractions must be made in
order to obtain a hydrometer reading corrected to the
80°F standard. For every 10° above 80°F, add four
specific gravity points (.004) to the hydrometer reading.
Example: A hydrometer reading of 1.260 at 110°F would
be 1.272 corrected to 80°F, indicating a fully charged
Battery. For every 10° below 80°F, subtract four points
(.004) from the reading. Example: A hydrometer reading
of 1.272 at 0°F would be 1.240 corrected to 80°F, indi-
cating a partially charged Battery.
Specific Gravity Cell Comparison Test—This test may
be used when a instrument tester is not available. To
perform this test measure the specific gravity of each
cell, regardless of state of charge, and interpret the
results as follows:
• If specific gravity readings show a difference be-
tween the highest and lowest cell of .050 (50 points)
or more, the Battery is defective and should be
replaced.
INSTALLING BATTERIES
To install a Battery properly, it is important to ob-
serve the following precautions:
• Connect grounded terminal of Battery last to avoid
short circuits which may damage the electrical
system.
CHEVROLET CHASSIS SERVICE MANUAL
ENGINE-ELECTRICAL 6Y-6
DO NOT SUCK
IN TOO MUCH
ELECTROLYTE
FLOAT MUST
BE FREE
TAKE READING
AT EYE LEVEL
• Be sure there are not foreign objects in the carrier,
so that the new Battery will rest properly in the
bottom of the carrier.
• Tighten the hold-down evenly until snug (60-80 in.
lbs.).
Do not draw down tight enough to distort or
crack the case or cover.
• Be sure the cables are in good condition and the
terminal clamps are clean and tight. Make sure the
ground cable is clean and tight at engine block or
frame.
• Check polarity to be sure the Battery is not reversed
with respect to the generating system.
Fig.
7b—Testing Specific Gravity
Fig.
8b--Battery Installation (Corvette Shown)
CHEVROLET CHASSIS SERVICE MANUAL
ENGINE-ELECTRICAL 6Y-7
CHARGING SYSTEM
INDEX
Page
General Description . 6Y-7
Maintenance and Adjustments 6Y-9
Static Checks . 6Y-10
System Condition Check and Voltage
•Regular Adjustment. 6Y-10
General Output 6Y-11
Generator Diode and Field Test 6Y-12
Indicator Lamp-Initial Field Excitation
Circuit Tests . 6Y-12
Page
Field Circuit Resistance Wire Tests 6Y-13
Field Relay Test and Adjustment 6Y-14
Other Harness Checks 6Y-14
Service Operations 6Y-14
Generator 6Y-14
Removal and Installation 6Y-14
Pulley Replacement. 6Y-14
Brush Replacement (6" Delcotron). 6Y-15
Double Contact Regulator . . . . . . 6Y-16
GENERAL DESCRIPTION
The charging system includes the battery, generator,
regulator, telltale light, and necessary wiring to connect
these components. The Delcotron is offered as standard
equipment, although there are various capacities avail-
able on all models.
The Delcotron continuous output A.C. generator (fig.
lc) consists of two major parts, a stator and a rotor. The
stator is composed of a large number of windings as-
sembled on the inside of a laminated core that is attached
to the generator frame. The rotor revolves within the
stator on bearings located in each end frame. Two
brushes are required to carry current through the two
slip rings to the field coils wound concentric with the
shaft of the rotor. Six rectifier diodes are mounted in the
slip ring end frame and are joined to the stator windings
at three internally located terminals.
Diodes are mounted in heat sinks to provide adequate
heat dissipation. The six diodes replace the separately
mounted rectifier as used in other types of application.
The diodes change the Delcotron A.C. current to D.C.
current.
Two regulators (fig. 2c) are available on the 1967 vehi-
cles,
a double contact two unit type and a transistor
regulator. The function of these regulators in the charg-
ing system is to limit the generator voltage to a pre-set
value by controlling the generator field current. Both
regulators have an internal field relay unit. The relay
unit allows the telltale lamp to light (as a bulb check)
with the ignition key on and engine not running. When the
engine is started and the generator begins to charge, the
indicator light goes out indicating that the system is op-
erating normally.
The double contact regulator, when used with the
special 63 amp air conditioning model generator (4 ohm
field coil) uses a field discharge diode internally in the
field circuit (figs. 3c and 4c). The added diode adapts the
BRUSH AND
TERMINAL
ASSEMBLY
SLIP RINGS
SLIP RING
END FRAME
_\
THRU
BOLT
DRIVE END
FRAME
BEARING
BEARING
DIODES
ROTOR
5.5" SERIES ID DELCOTRON
STATOR
ASSEMBLY
GREASE
RESERVOIR
BRUSH
FAN ASSEMBLY
6.2" SERIES 2D TYPE 150 DELCOTRON
Fig.
lc—Delcotron Cross-section View
CHEVROLET CHASSIS SERVICE MANUAL
ENGINE-ELECTRICAL 6Y-8
1
FIELD RELAY^I^p2
"LATCH"
^PFN?^
"P1
TERMINAL
JyJvJCTl^
NO. 2 TERMINAD^5^^^«
NO.
3 TERMINAL ^S5«£
NO.
4 TERMINAL ^^^
m
# / VOLTAGE
¥ REGULATOR
1
ACCESS PLUG TO
VOLTAGE ADJUSTMENT
No 4 TERMINAL
Double Contact
Fig.
2c—Voltage Regulator Assemblies
Transistor
regulator to handle the higher field current and enables it
to absorb the increased inductive voltages of the field
coil with satisfactory contact point life.
The double-contact regulator assembly (fig. 2c) con-
sists of a double contact voltage regulator unit and a field
relay unit. This unit uses two sets of contact points on
the voltage regulator unit to obtain desired field excita-
tion under variable conditions. Internal circuit wiring
diagrams of the double contact regulator are shown in
Figures 3c and 4c.
The transistor regulator (fig. 2c) is an assembly com-
posed principally of transistors, diodes, resistors, a
capacitor, and a thermistor to form a completely static
voltage regulating unit in combination with a conventional
vibrating type field relay.
The transistor is an electrical device which limits the
generator voltage to a preset value by controlling the
generator field current. The diodes, capacitor and re-
sistors act together to aid the transistors in controlling
the generator voltage. This is the only function that the
regulator performs in the charging circuit. The
thermistor provides a temperature-compensated voltage
setting. Wiring diagrams of the transistor regulator are
shown in Figures 3c and 4c.
The voltage at which the generator operates is deter-
mined by the regulator adjustment. The regulator voltage
setting can be adjusted externally by removing a pipe plug
in the cover (fig. 2c) and turning the adjusting arm inside
the regulator. This procedure is explained in the followr
ing section, and permits regulator adjustments without
removing the cover.
FUSIBLE
DOUBLE CONTACT
FUSIBLE LINK-^
JUNCTION HORN
BLOCK RELAY
RESISTOR
Q FIELD Q>
DELCOTRON TR-
TRANSISTOR
FUSIBLE LINK-
Fig.
3c-Circuity - Voltage Regulator Assemblies (Except Corvette)
CHEVROLET CHASSIS SERVICE MANUAL
ENGINE-ELECTRICAL 6Y-9
63 AMP 1
MODELS ONLY'
BATTERY FUSIBLE
LINK
HORN
FUSIBLE LINK'
TRANSISTOR
FUSIBLE LINK'
Fig.
4c— Circuitry - Voltage Regulator Assemblies (Corvette)
Engine compartment wiring harness incorporates sev-
eral fusible links. Each link is identified with its gage
size. A fusible link is a length of special wire (normally
four wire gages smaller than the circuit it is protecting)
used in wiring circuits that are not normally fused, such
as the ignition circuit. The same size wire with a hypalon
insulation must be used when replacing a fusible link.
The links are:
1.
The pigtail lead at the battery positive cable (except
Corvette) is a 14 gage, brown fusible link protecting
the 10 gage battery charging circuit. This wire is an
integral part of the battery cable assembly and serv-
icing requires replacing the complete battery cable
assembly. On Corvette models this link is installed
as a molded splice at the solenoid "Bat" terminal
and servicing requires splicing in a new link.
2.
A 16 gage black fusible link is located at the horn
4.
relay to protect all unfused wiring of 12 gage or
larger. It is installed as a molded splice and serv-
icing requires splicing in a new link.
The generator warning light and field circuitry (16
gage wire) is protected by a fusible link (20 gage
orange wire) used in the "battery feed to voltage
regulator #3 terminal" wire. The link is installed as
a molded splice in the generator and forward lamp
harness and is serviced by splicing in a new 20 gage
wire as required.
The ammeter circuit on all models is protected by
two orange, 20 gage wire fusible links installed as
molded splices in the circuit at the junction block or
the solenoid "Bat" terminal (Corvette only) and at
the horn relay. Each link is serviced by splicing in a
new 20 gage wire as required.
MAINTENANCE AND ADJUSTMENTS
At regular intervals, inspect the terminals for cor-
rosion an4 loose connections, and the wiring for frayed
insulation. Check mounting bolts for tightness. Check the
drive belt for alignment, proper tension and wear. Be-
cause of the higher inertia and load capacity of the rotor
used in A.C. generators, PROPER BELT TENSION is
more critical than on D.C. generators.
Since the Delcotron and its companion regulator are
designed for use on negative polarity systems only, the
following precautions must be observed. Failure to ob-
serve these precautions may result in serious damage to
the charging system.
1.
When installing a battery, always make absolutely
sure the ground polarity of the battery, generator and
regulator is the same.
2.
When connecting a booster battery, make certain to
connect the correct battery terminals together.
3.
When connecting a charger to the battery, connect the
correct charger leads to the battery
%
terminals.
4.
Never operate the generator on an uncontrolled open
TO SOLENOID
BAT ACC RES. WIRE
Fig.
5c—Typical Wiring Diagram Showing Lead Connections
CHEVROLET CHASSIS SERVICE MANUAL