charging CHEVROLET CAMARO 1967 1.G Chassis User Guide

HEATER AND AIR CONDITIONING 1A-46

MAKE ANGULAR CUT

FOR HOSE REMOVAL

LOCATING

BEAD

SEALING

BEADS
LOCATING

BEAD
not to nick or score the sealing beads when

cutting off the hose. Cutting the hose lengthwise

may result in this problem.

Fig.
58—Hose Clamp Connections

NOTE:
Where steel to aluminum connections

are being made, use torque for aluminum tubing.

Hose Clamps (Fig. 58)

When hose clamp connections are encountered special

procedures are necessary for both installation and

removal.

Installation

1.
Coat tube and hose with refrigeration oil.

2.
Carefully insert hose over the three beads on the

fitting and down as far as the fourth, or locating,

bead. Hose must butt against this fourth bead.

CAUTION: Use no sealer of any kind.

3.
Install clamps on hose, hooking the locating arms

over the cut end of the hose.

4.
Tighten the hose clamp screw to 35-42 lb. in.

(except Corvette) 30-38 lb. in. (Corvette). DO NOT

RETORQUE.

Removal

1.
Carefully, with a sharp knife, make an angle cut in

the hose as shown in Figure 58. This should loosen

the hose so that it may be worked off the fitting.

2.
Cut off slit end of hose when reinstalling. Reinstall

as described above.

CAUTION: Use only approved refrigeration

hose. Never use heater hose. Use extreme care
REPAIR OF REFRIGERANT LEAKS

Any refrigerant leaks found in the system should be

repaired in the manner given below:

Leaks at "O" Ring Connection

1.
Check the torque on the fitting and, if too loose,

tighten to the proper torque. Always use a backing

wrench to prevent twisting and damage to the "O"

ring. Do not overtighten. Again leak test the joint.

2.
If the leak is still present, discharge the refrigerant

from the system as described under "Evacuating

and Charging Procedures."

3.
Inspect the ''O" ring and the fitting and replace if

damaged in any way. Coat the "O". ring before re-

installed with refrigerati6n oil and install carefully.

4.
Retorque the fitting, using a backing wrench, and

then add 1/2 to 1 lb. of R-12 to the system and

recheck for leaks.

CAUTION: Do not operate the system with this

small refrigerant charge.

5. Purge the system, thus removing the 1/2 to 1 lb.

installed in Step 4 above.

6. Evacuate and charge the system.

Leaks at Hose Clamp Connection

1.
Check the tightness of the clamp itself and tighten

if necessary. Recheck for leak.

2.
If leak has not been corrected discharge the system

and loosen clamp and remove hose from connection.

Inspect condition of hose and connector. Replace

scored or damaged parts.

3.
Dip end of new hose in refrigerant oil and carefully

reinstall over connector. Never push end of hose

beyond the locating bead. Properly torque the clamp.

4.
Recheck the system for leaks by installing 1/2 to 1

lb.
of R-12 into the system. Do not run compressor.

5. Purge. the system, thus removing the 1/2 to 1 lb.

installed in Step 4 above.

6. Evacuate and charge the system.

Compressor Leaks

If leaks are located around the compressor shaft seal

or shell, replacement of necessary seals should be made

as outlined under "Compressor" in the Chassis Overhaul

Shop Manual.

REFRIGERANT HOSE FAILURE

After a leak or rupture has occurred in a refrigerant

hose, or if a fitting has loosened and caused a consider-

able loss of refrigerant and oil, the entire system should

be flushed and recharged after repairs have been made.

Ji the system has been open to atmosphere for any pro-

longed period of time the receiver-dehydrator should be

replaced.

PREPARING SYSTEM FOR REPLACEMENT

OF COMPONENT PARTS

Air conditioning, like many other things, is farily

simple to service once it is understood. However, there

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-53

Fig.
70—Wiring and Vacuum Lines—Four-Season (Camaro)

Installation

1.
Connect the expansion valve to the refrigerant pipes.

Attach the capillary bulb to the evaporator.

2.
Attach the evaporator to the- case. Attach the inlet

and outlet pipes clamps.

3.
Assemble the case halves. Insert the capillary tube

from the thermostatic switch between the fins as

shown in Figure . Attach the cover plate to the

case.

4.
Mount the unit to the dash and connect the refrigerant

lines.

5.
Evacuate and charge the system. If a new evaporator

was installed, add three fluid ounces of refrigerant

oil to the system before charging.

6. Test system operation.

Chevy II All-Weather System

Removal

Under
the Hood

1.
Purge the refrigerant from the system.

2.
Remove the refrigerant hoses from the evaporator

inlet and outlet connections extending through the

special grommet in the dash panel and into the

engine compartment.

3.
Remove the screw, nut, spacer bracket and grommet

from the outlet connection pipes.
Within the Car

4.
Remove the glove box, ash tray and ash tray

retainer.

5.
Reach through the glove box door to disconnect the

air conditioning "on" door bowden cable (fig. 75).

6. Remove the two shield attaching screws and shield

(A, fig. 76) which covers the lower right evaporator

bracket-to-blower bracket attaching screw (B, fig.

76),
then remove this screw.

7.
Behind the lower left side of ihe evaporator, remove

the evaporator bracket-to-heater distributor bracket

attaching screw (C, fig. 76).

8. Reaching through the glove box door and ash tray

openings, remove the two nuts and washers (D,

fig.
76) attaching the evaporator assembly studs to

the lower instrument panel flange and reinforcement.

9. Disconnect the drain hoses and carefully pull the

evaporator unit toward the rear of the vehicle.

10.
Disconnect wiring connectors (see fig. 77) as nec-

essary and remove the evaporator unit from the

vehicle.

Gore and/or Expansion Valve Replacement

A defective unit must be replaced since repairs should

never be made on the evaporator core. Before replacing

the core, however, check to be sure that any leaks pres-

sent are not located at the hose connections or expansion

valve connections. The following procedure assumes that

the evaporator unit has been removed from the vehicle

as outlined above.

CHEVROLET CHASSIS SERVICE MANUAL

HEATER
AND AIR
CONDITIONING
1A-84

SPECIAL TOOLS

18
19 20 21 23 24
28
30

32

Fig.
120—Air Conditioning—Special Tools

1.

1A.

IB.

2.

3.

4.

5.

6.

7.
00*

9.

10.

11.

12.

13.

14.

15.
J-8393

J-22368

J-21530

J-5453

J-9459

J-5420

J-6084

J-8433

J-9395

J-6272

J-6271

J-7151

J-5421

J-5403

J-6435

J-9396

J-9397
Charging Station

Comfortron System fester

Comfortron Temperature Dial Adjuster

Goggles

90° Gauge Line Adapter

Gauge Line Adapter

Leak Detector

Puller

Puller Pilot

No.
3
Multi-Opener (3-Can)

Fitzall Valve (Single
Can)

Non-Magnetic Clutch Shims

Pocket Thermometers
(2)

#21 Snap Ring Pliers

#26 Snap Ring Pliers

Compressor Holding Fixture

Compressing Fixture
16.
J-9403

17.
J-9399

18.
J-9401

19.
J-9480

20.
J-9392

21.
J-9393

22.
J-9298

23.
J-9481

24.
J-8092

25.
J-9521

26.
J-5139

27.
J-9432

28.
J-9553

29.
J-21508

30.
J-21303

31.
J-9527

,
32.
J-9402
Clutch
Hub
Holding Tool

9/16" Thin Wall Socket

Hub
and
Drive Plate Assembly Remover

Hub
and
Drive Plate Assembly Installer

Seal Remover

Seal Seat Remover

Pulley Bearing Remover

Pulley and Bearing installer

Handle

Internal Assembly Support Block

Oil Pickup Tube Remover

Needle Bearing Installer

Seal Seat "O" Ring Remover

Seal Seat "O" Ring Installer

Shaft Seal Protector

Pressure Test Connector

Parts Tray

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE
6-5

Service Battery and Battery Cables

1.
Measure the specific gravity of the electrolyte in

each cell (fig. 6). If it is below 1.230 (corrected to

80°F.) recharge with a slow rate charger, or if de-

sired, further check battery.

2.
Connect a voltmeter across the battery terminals and

measure the terminal voltage of the battery during

cranking (disconnect the coil primary lead at the

negative terminal during this check to prevent engine

from firing). If the terminal voltage is less than 9.0

volts at room temperature, approximately 80°

±
20°
F.,
the battery should be further checked. See

Section 6Y for further tests.

3.
Inspect for signs of corrosion on battery, cables and

surrounding area, loose or broken carriers, cracked

or bulged cases,- dirt and acid, electrolyte leakage

and low electrolyte level. !Fill cells to proper level

with distilled water or water passed through a

"demineralizer".

The top of the battery should be clean and the bat-

tery hold-down bolts properly tightened. Particular

care should be taken to see that the top of the battery

is kept clean of acid film and dirt. When cleaning

batteries, wash first with a dilute ammonia or soda

solution to neutralize any acid present and then flush

off with clean water. Keep vent plugs tight so that

the neutralizing solution does not enter the cell. The

hold-down bolts should be kept tight enough to prevent

the battery from shaking around in its holder, but

they should not be tightened to the point where the

battery case will be placed under a severe strain.

To insure good contact, the battery cables should

be tight on the battery posts. Oil battery terminal

felt washer. If the battery posts or cable terminals
are corroded, the cables should be cleaned separately

with a soda solution and wire brush. After cleaning

and before installing clamps, apply a thin coating of

petrolatum to the posts and cable clamps to help

retard corrosion.

If the battery has remained undercharged, check

for loose or defective fan belt, defective Delcotron,

high resistance in the charging circuit, oxidized

regulator contact points, or a low voltage setting.

If the battery has been using too much water, the

voltage output
is-
too high.

Service Deicotron and Regulator

The Delcotron and regulator tests during tune up con-

sist of the above battery tests; the condition of the battery

indicating further tests and adjustments as outlined in

Section 6Y.

Service Belts (Fig. 7)

Inspect belt condition.

Check and adjust if necessary for correct tension of

belt, as follows:

• Using a strand tension gauge, check the belt tension.

• Adjust belt until the specified tension is reached.

(See Tune Up Chart.)

Service Manifold Heat Valve (Figs. 8 or 9)

Check manifold heat control valve for freedom of oper-

ation. If shaft is sticking, free it up with GM Manifold

Heat Control Solvent or its equivalent.

NOTE: Tap shaft end to end to help free it up.

Tighten Manifold

Tighten intake manifold bolts to specifications in the

FLAME

ARRESTOR
FLAME

ARRESTOR

NON-VENTED\

CAP
V\ VALVE

CLOSED
POSITIVE (283 & 327)

POSITIVE
(IN LINE)

POSITIVE
(327)

POSITIVE
(396 & 427)

Fig.
10 -
Crank case
Ventilation Systems

CHEVROLET CHASSIS SERVICE MANUAL

SECTION 6Y

ENGINE ELECTRICAL

CONTENTS
OF
THIS SECTION

Page

System

6Y-19
6Y-32

6Y-34

BATTERY

INDEX

Page

General Description 6Y_i

Types of Batteries 6Y-1

Dry Charged Batteries 6Y-2

Activating Dry Charged Batteries 6Y-2

Wet Charged Batteries 6Y 2

Periodic Service 6Y-3

Common Causes of Failure 6Y-3

Delco Eye 6Y_3

Electrolyte Level
AY
3

Water Usage ] \ 6Y_3

Cleaning 6Y_4

Cables 6Y_4

Carrier and Holddown 6Y-4
Page

Safety Precautions 6Y-4

Charging Procedures . . gY_4

Slow Charging gY-4

Fast Charging . * 6Y-4

Emergency Boost Charging 6Y-4

Test Procedures QY-S

Visual Inspection 6Y-5

Instrument 6Y-5

Full Charge Hydrometer Test. 6Y-5

Specific Gravity Readings 6Y-5

Cell Comparison Test . 6Y-5

Installing Battery 6Y-5

GENERAL DESCRIPTION

The battery (fig. lb) is made up of a number of separ-

ate elements, each located in an individual cell in a hard

rubber case. Each element consists of an assembly of

positive plates and negative plates containing dissimilar

active materials and kept apart by separators. Hie ele-

ments are immersed in an electrolyte composed of dilute

sulfuric acid. Plate straps located on the top of each ele-

ment connect all the positive plates and all the negative

plates into groups. The elements are connected in series

electrically by connectors that pass directly through the

case partitions between cells. The battery top is a one-

piece cover of hard rubber construction. Tfte cell con-

nectors, by-passing through the cell partitions, connect

the elements along the shortest practical path (fig. 2b).

With the length of the electrical circuit inside the

Battery reduced to a minimum, the internal voltage drop

is decreased resulting in improved performance, par-

ticularly during engine cranking at low temperatures.

The hard, smooth one-piece cover greatly reduces the

tendency for corrosion to form on the top of the Battery.

The cover is bonded to the case with sealing compound

that forms an air tight seal between the cover and case.

Protection for the Battery charging circuit (10 gage

wire) is provided by a pigtail lead which is a fusible Hnk

off the battery positive cable (14 gage wire). This lead is

an integral part of the Battery cable assembly and serv-

icing requires replacing the complete cable assembly.

TYPES
OF
BATTERIES

There are two types of Batteries—the "dry charge"

type and the "wet charge" type. The difference in types

depends on the method of manufacture.
ONE PIECE

CELL COVER

VENT PLUG
ELECTROLYTE LEVEL

INDICATOR

HOLD-DOWN SLOT

Fig.
lb—Battery

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-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