light CHEVROLET CAMARO 1967 1.G Chassis Repair Manual

ENGINE FUEL 6M-4

Fig.
3C-Fuel Level Sight Plug

2.
Push hand choke knob in to within 1/8" of instru-

ment panel.

3.
Loosen choke cable clamp at carburetor bracket and

adjust cable through the clip until the choke valve

is wide open.

4.
Tighten cable clamp at carburetor bracket and check

operation of choke valve to ensure full closed and

wide open positions.

5. Install air cleaner.

Float Adjustment

Ho/fey (Model 4150
Center
Inlet & Model 2300)

1.
Remove air cleaner then remove the fuel level sight

plugs (Fig. 3c)

2.
With parking brake on, and transmission in neutral,

start the engine and allow it to idle.

3.
With the car on a level surface, the fuel level should

be on a level with the threads at the bottom of the

sight plug port (plus or minus 1/32 inch).

NOTE:
No float drop adjustment is required

on this carburetor.

4.
If necessary to adjust (either or both bowls), loosen

inlet needle lock screw and turn the adjusting nut

clockwise to lower or counter-clockwise to raise

fuel level, then tighten lock screw.

NOTE:
1/6 turn of adjusting nut equals ap-

proximately 1/16" fuel level change.

5. Allow a minute for fuel level to stabilize then re-

check the level at sight plug.

6. Readjust, if necessary, until proper level is obtained,

then install sight plug and air cleaner.

NOTE:
To assure proper secondary float level

setting it is advisable to accelerate primary

throttles slightly and hand operate secondary
throttle. This assures a stabilized secondary

fuel level.

Additional Adjustments

The following adjustments may be made without re-

moving the carburetor from the engine. For procedure

refer to Section 6M of the Overhaul Manual under the

carburetor being serviced.

Rochester BV

• Float

• Idle Vent

• Choke Rod (Fast Idle)

• Choke Vacuum Break

• Choke Unloader

Rochester 2GV

• Float

• Accelerator Pump

• Idle Vent

• Choke Rod (Fast Idle)

• Choke Vacuum Break

• Choke Unloader

• Secondary Throttle Opening

• Secondary Throttle Lockout

Rochester 4MV

• Float

• Accelerator Pumj)

• Idle Vent

• Air Valve

• Choke Rod

• Choke Vacuum Break

• Choke Unloader

• Air Valve Lockout

• Secondary Opening

• Secondary Lockout

Carter YF

• Float

• Idle Vent

• Choke Rod (Fast Idle)

• Choke Vacuum Break

• Choke Unloader

Holley 4160 and 4150
(Except End
Inlet)

• Float

• Air Vent Valve

• Accelerator Pump

• Choke Vacuum Break

• Choke Unloader

Holley 2300 and 4150
(End
Inlet)

• Air Vent Valve (except 2300)

• Accelerator Pump

• Choke Vacuum Break

• Choke Unloader

Removal

Flooding, stumble on acceleration and other perform-

mance complaints are, in many instances, caused by the

presence of dirt, water, or other foreign matter in the

carburetor. To aid in diagnosing the cause of the com-

plaint, the carburetor should be carefully removed from

the engine without draining the fuel from the bowl.

The contents of the fuel bowl may then be examined for

contamination as the carburetor is disassembled.

1.
Remove air cleaner and gasket.

2.
Disconnect fuel and vacuum lines from carburetor.

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE FUEL 6M-8

^T^l^^/'-vN

COVER
BOTTOM

Fig. 1A—Polyurethane Element Air Cleaner
OIL RESISTANCE

SEAL

BOTTOM
BONDED PAPER

ELEMENT

COVER

Fig. 2A—Paper Element Air Cleaner

SERVICE
PROCEDURES

POLYURETHANE ELEMENT

Maintenance

1.
Remove cover wing nut, cover and filter element.

2.
Visibly check the element for tears or rips and re-

place if necessary.

3.
Clean all accumulated dirt and grime from air

cleaner bottom and cover. Discard air horn to air

cleaner gasket.

4.
/Remove support screen from element and wash

element in kerosene or mineral spirits; then squeeze

out excess solvent (fig. 3A).

NOTE: Never use a hot degreaser or any sol-

vent containing acetone or similar solvent*

5.
Dip element into light engine oil and squeeze out

excess oil.
NOTE: Never shake, swing or wring the ele-

me.nt to remove excess oil or solvent as this

may tear the polyurethane material. Instead,

"squeeze" the excess from the element.

6. Install element'on screen support (fig. 4A).

7.
Using a new gasket, replace air cleaner body over

carburetor air horn.

8. Replace the element in the air cleaner. Care must

be taken that the lower lip of the element is properly

placed in the assembly and that the filter material

is not folded or creased in any manner that would

cause an imperfect seal. Take the same precautions

when replacing the cover that the upper lip of the

element is in proper position.

9.<•
Replace cover and wing nut.

OIL BATH

Maintenance

L Remove air cleaner assembly.

2.
Remove cover and filter element assembly.

Empty oil out of

accumulated dirt.
cleaner and clean out all oil and

Fig. 3A—Cleaning Polyurethane Element

Fig.
4A—Polyurethane Support

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE FUEL 6M-9

4.
Wash body with cleaning solvent and wip dry.

5. Wash filter element by sloshing up and down in

cleaning solvent.

6. Dry filter unit with an air hose or let stand until

dry.

7. Fill body of cleaner to full mark with SAE 50 engine

oil. If expected temperatures are to be consistently

below freezing, use SAE 20 engine oil.

8. Assemble filter and cover assembly to body of

cleaner.

9. Install cleaner, making sure it fits tight and is set

down securely. \

OIL
WETTED
PAPER
ELEMENT

Replacement

1.
Remove wing nut, washer and cover.

2.
Remove paper element and discard.

3.
Remove bottom section of air cleaner and gasket

on air horn of carburetor. Discard air horn gasket.

4.
Clean bottom section of air cleaner and cover pieces

thoroughly, to remove dust and grime.

NOTE:
Check bottom section of air cleaner

seal for tears or cracks.

5. Install a new gasket on carburetor air horn and set

bottom section of air cleaner on carburetor.

6. Install new paper element on bottom section of air

cleaner with either end up.

NOTE:
Plastisol seal is the same material on

both ends.

7. Install cover, washer and wing nut.

Testing (Fig. 5A)

Tool J-7825, is designed to check paper element air

cleaners to determine whether the element has ma-

terially decreased in efficiency arid should be replaced

or has only slightly increased air restriction and is

suitable for further service. In combination with a

tachometer, this instrument will quickly and accurately

determine the air cleaner element condition.

VENT HOLE

TOWARD DASH
NOTE:
t Before testing, inspect for holes or

breaks in the element, as these defects re-

quire immediate replacement. If no holes or

breaks exist, proceed as follows:

1.
Remove all hoses and plug all openings except air

cleaner inlet.

2.
Install air cleaner, using Tool J-7825 in place of the

wing nut. Screw Tool J-7825 onto the stud until it

seals tightly against the air cleaner cover. Rotate

the entire tool so that the scale can be read from

the left side of the car. Be sure the vent hole is

toward the dash.

3.
Connect a tachometer and place it so that it may be

read simultaneously with Tool J-7825.

4.
Zero oil level in the inner tube by pulling inner tube

upward until the rubber seal is above the vent hole,

then raise or lower as' required until the inner tube

oil level is exactly to the "0" mark.

5. Start engine. If engine is cold, allow to run for 2 to

3 minutes. The automatic choke must be fully open.

6. Accelerate the engine slowly until the inner tube oil

level of Tool J-7825 just reaches the 1/4 mark.

Allow engine speed to stabilize and note tachometer

(rpm) reading. Decelerate engine.

7. If the tachometer reading is at or below the follow-

ing, the oil wetted paper air cleaner element is re-

stricted beyond the allowable limit and should be

replaced. If testing indicates that the element

restriction is satisfactory at 12,000 miles, the ele-

ment need not be replaced but should be retested

every 6,000 miles thereafter until replaced.

Engine

Displacement

283 cu.
in.

327 cu.
in.

350 cu. in.

396 cu.
in.

427 cu.
in.
Horsepower

195

210

275

300

325

350

295

325

350

385

390

425
Minimum

Allowable

RPM

2300

2100

210Q

2600

2600

1550

1950

1850

1850

2140

Fig.
5A—Testing Air Cleaner
8. Remove tachometer and Tool J-7825 from vehicle

and push down inner tube until seal is below vent

hole to prevent oil loss.

Tool J-7825

FiHing
Tool

Tool J-7825 is shipped dry and must be filled with the

red gauge oil (specific gravity .826) provided.

Pull the knurled inner tube completely out of the gauge

and add oil to the reservoir until the oil level is between

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-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-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

ENGINE-ELECTRICAL 6Y-10

circuit. Make absolutely certain all connections in

the circuit are secure.

5.
Do not short across or ground any of the terminals

on the generator or regulator.

6. Do not attempt to polarize the generator.

7.
Do not disconnect lead at generator without first dis-

connecting battery ground cable.

Trouble in the A.C. charging system will usually be

indicated by one or more of the following conditions:

1.
Faulty indicator lamp or ammeter operation.

2.
An undercharged battery (usually evidenced by slow

cranking speeds).

3.
An overcharged battery (usually evidenced by exces-

sive battery water usage).

4.
Excessive generator noise or vibration.

Described below are a series of on-the-vehicle quick

checks which are designed to assist the service tech-

nician in locating troubles within the various components

of the engine electrical system. Additional checks, ad-

justments and overhaul procedures of these components

are also described in the "Charging Systems—Service

Operations Section" and should be referred to as

necessary.

STATIC CHECKS

Before making any electrical checks, perform the fol-

lowing static checks:

1.
Check for loose fan belt.

2.
Check for defective battery. (Refer to Battery).

3.
Inspect all connections, including the slip-on con-

nectors at the regulator and Delcotron.

NOTE: Do not short field to ground to check if

generator is charging since this will seriously

damage the charging system.

SYSTEM CONDITION TEST

This test is used .to indicate the overall condition of the

charging system (both good and defective) and to isolate

the malfunctioning unit if the system is defective.

NOTE: On Corvette models difficulty may be

encountered -when attempting to make the re-
quired test connections at the voltage regulator.

It is advisable to remove the regulator from its

mounting location to perform the necessary con-

nections at the regulator for the following tests

but make sure unit is grounded.

1.
With ignition off, perform the prescribed Static

Checks outlined in this section. Then set hand brake

and shift transmission
into
neutral.

2.
Connect a voltmeter from junction block relay to

ground at regulator base.

CAUTION: Be sure meter clip does not touch a

resistor or terminal extension under regulator,

3.
Connect a tachometer on engine.

4.
Models equipped with Indicator Lamp: Turn ignition

switch on "ON" position and check indicator lamp.

If lamp fails to glow, perform appropriate tests and

corrections (Indicator Lamp Circuit Tests) before

continuing.

Models equipped with Ammeter: Turn ignition

switch to "ACC" with an accessory on and check

ammeter. If ammeter fails to read discharge, check

ammeter circuit before continuing.

5.
Models equipped with Indicator Lamp: If lamp glows,

start the engine and run' it at 1500 rpm or above.

Check indicator lamp. If lamp fails to go out, per-

form appropriate test and corrections (Indicator

Lamp Circuit Test) before continuing.

Models equipped with Ammeter: If ammeter reads

discharge, start the engine and observe ammeter. If

meter fails to move toward charge (from original

position), perform appropriate test and corrections

(Field Circuit Tests) before continuing.

NOTE: At this point a field circuit has been

established and any other problem will lie in

generator or regulator.

6. Turn on high-beam headlights and heater blower

motor to high speed, run engine at or above 1500

rpm (for a few minutes, if necessary) and read the

voltage on meter.

AIR GAP

ADJUSTING NUT

ONLY

ADJUSTING SCREW

(Turn To Adjust

Voltage Setting)

Fig.
6c—Adjusting Voltage Setting

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE-ELECTRICAL 6Y-J2

Fig.
8c—Ammeter Method Test Connections

10.
Turn off ignition, disconnect battery ground cable,

and remove all test equipment.

11.
li the Delcotron meets the test specifications, the

problem is not in the generator.

12.
Ti the Delcotron fails to meet the test specifications,

remove it and perform bench tests and make repair

needed.

DELCOTRON DIODE AND FIELD TEST (Fig. 9c)

NOTE:
These tests will indicate good,, shorted

or open field or shorted diode but will not indi-

cate a failed open diode. If output was low and

following tests show good, refer to service op-

erations to determine cause and repair.

1.
Disconnect battery ground cable at battery.

2.
Positive diodes (Test A) connect an ohmmeter be-

tween "R" terminal and "BAT" terminal and note

Fig.
9c-Deicotron Diode and Field Test
reading, then reverse the leads at same terminals

and note this reading. Meter should read high re-

sistance in one direction and low in the other.

3.
Negative diodes (Test B) connect ohmmeter between

"R" terminal and "GRD" and note reading, then

reverse the leads and note this reading. Meter

should read high in one direction and low in the

other.

NOTE:
A high or low reading in both directions

indicates a defective diode.

4.
Open Field Check:

a. Connect an ohmmeter from "F" terminal to

"GRD"
terminal stud and note reading on the

lowest range scale. Meter should read 7 to

20 ohms.

b.
If meter reads zero or excessively high resist-

ance, the Delcotron is faulty.

5. If above tests indicate a defective Delcotron, remove

and completely check Delcotron as outlined under

''Service Operations".

INDICATOR LAMP/INITIAL FIELD

EXCITATION CIRCUIT TESTS (Fig. 10c)

On standard models the indicator lamp circuit provides

initial field excitation (causing lamp to glow). The light

is cancelled by closing the field relay which applies bat-

tery voltage to both sides of bulb (bulb goes out).

The indicator light should glow when ignition switch is

"ON"
and go out almost immediately when engine starts.

Ammeter equipped vehicles use the same initial field

excitation and control circuits as the indicator lamp ex-

cept the lamp is omitted. The continuity tests on both

type vehicles can be made as follows:

If Lamp Fails to Glow or Ammeter Fails to

Function the Possible Causes are:

1.
Faulty bulb or bulb socket.

2.
Faulty ammeter.

3.
An open circuit in wiring, regulator, or field.

4.
A shorted positive diode—(may also cause glow with

ignition switch "OFF").

TEST AS FOLLOWS:

1.
Disconnect connector from regulator and turn

ignition switch to "ON". Connect a test lamp from

connector terminal "4" to ground (fig. 10c, Step 1)

and note test lamp.

a. Lamp fails to glow—check for faulty bulb, socket

or open circuit between switch and regulator con-

nector. Repair as needed.

b.
Light goes on—failure is in regulator, Delcotron,

or wire between "F" terminals on regulator and

Delcotron. Go to Step 2.

2.
Disconnect lamp lead at ground end and connect be-

tween connector "F" and "4" terminals (fig. 10c,

Step 2), and note lamp:

a. Test Lamp glows—problem is in regulator. An

open circuit in regulator or relay is stuck dosed.

See "Service Operations" for repair.

b.
Fails to glow—problem is in wire between "F"

terminals on generator and regulator or infield

windings. Go to Step 3.

3.
Disconnect test lamp at connector "F" terminal and

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE-ELECTRICAL 6Y-14

VOLTMETER

WIRING HARNESS

CONNECTOR

Fig.
12c—Field Relay Closing Voltage Test

FIELD RELAY CHECKS AND ADJUSTMENT

To check for a faulty relay proceed as follows:

1.
Connect a voltmeter into the system at the regulator

No.
2 terminal to ground (fig. lie).

2.
Operate the engine at fast idle (1500 to 2000 rpm) and

observe voltmeter reading.

3.
If voltmeter shows zero voltage at regulator, check

circuit between No. 2 terminal on regulator to "R"

terminal on Delcotron.

4.
If voltage at regulator exceeds closing voltage
Fig.
13c—Adjusting Field Relay Closing Voltage

specification and light remains on, regulator field

relay is faulty (Refer to specifications). Check and

adjust regulator as follows:

CLOSING VOLTAGE ADJUSTMENT

•1.
Make connections as shown in Figure 12c using a 50

ohm variable resistor.

NOTE: This gives us a variable resistance in

series from a hot lead to the relay coil.

2.
Turn resistor to "open" position.

3.
Turn ignition switch off.

4.
Slowly decrease resistance and note closing voltage

of the relay. Adjust by bending heel iron in the man-

ner illustrated in Figure 13c.

OTHER HARNESS CHECKS

Other wires in the charging system harness need be

checked for continuity by use of an ohmmeter or a test

ligjit (12 Volt). Connect the test so the wire in question is

in series in the test circuit.

SERVICE OPERATIONS

Service Procedures described in this section are for

the 5.5" aluminum and 6.2" perforated stator Delcotrons

(fig. 14c). Where important differences are encountered

separate mention will be made of the two generators.

GENERATOR

REMOVAL AND INSTALLATION

1.
Disconnect the battery ground strap at battery to

prevent damaging diodes.

2.
Disconnect wiring leads at Delcotron.

3.
Remove generator brace bolt, (if power steering

equipped, loosen pump brace and mount nuts) then

detach drive belt (belts).

4.
Support the generator and remove generator mount

bolt (6.2" Delcotron uses 2 mount bolts) and remove

from vehicle.
5.
Reverse the removal procedure to install then adjust

drive belt.

PULLEY REPLACEMENT

5.5" Delcotron

Single Groove Pulley

1.
Place 15/16" box wrench on retaining nut and insert

a 5/16" alien wrench into shaft to hold shaft while

removing nut (fig. 15c).

2.
Remove washer and slide pulley from shaft.

3.
Reverse Steps 1 and
2
to install, use a torque wrench

with a crow-foot adapter (instead of box wrench) and

torque the nut to 50 ft. lbs. (fig. 16c).

Double Groove Pulley

1.
Place a 15/16" socket (with wrench flats on the drive

CHEVROLET CHASSIS SERVICE MANUAL