1967 CHEVROLET CAMARO Chassis Workshop 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-13

F 2 3 4

f 2 3 4

F 2 3 4

Fig.
10c—Initial Field Excitation Circuit Tests

connect to "F" terminal on Delcotron (fig. 10c,

Step 3), and note lamp:

a. Lamp glows-an open circuit in wire between "F"

terminals—correct as needed.

b.
Fails to glow—Delcotron field has open circuit,

see "Service Operations" to repair %

If Lamp Fails to Go Out, or if Ammeter Shows

Discharge the Possible Causes are:

1.
Loose drive belt—adjust as necessary.

2.
Faulty field relay—(see relay test and adjustment).

3.
Defective Delcotron—(see Delcotron output test).

4.
At normal idle—parallel resistance wire open (see

Resistance test). On ammeter models the initial

field excitation wire to "ACC" terminal is open.

5. Switch off—positive diode shorted (see Diode test).

FIELD CIRCUIT RESISTANCE

WIRE CHECKS

The resistance wire is an integral part of the ignition

harness. However, the resistance wire is not solderable;

it must be spliced with a crimp-type connector. It is

rated at 10 ohms, 6.25 watts minimum.

The check for an open resistor or field excitation wire

(connected to the ignition switch "ACC" terminal) is as

follows:

1.
Connect a test lamp from the wiring harness con-

nector terminal "4" to ground as shown in Figure

10c (Step 1).

2.
Turn the ignition switch to the "ON" position and

note test bulb.

a. Test lamp glows—resistance is O.K.

b.
Test lamp does not glow—the resistor is open

circuited—note also that dash lamp does not glow

during this test because series resistance of the

2 bulbs causes amperage to be too low.
VOLTMETER

3 4

WIRING*
HARNESS

CONNECTOR

Fig.
11c—Testing Field Relay

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

ENGINE-ELECTRICAL 6Y-15

L
RELAY

TERMINAL "F" TERMINAL

"BAT" \ ' /

TERMINAL
/ / /
GRD7
TERMINAL

5.5" SERIES ID DELCOTRON
"BAH"

TERMINAL

^Vs^^^^lijBii^^8C^3^SH|j^^^^^^sH^^Bf- y/

RELAY ^^^"^^^jWwIi^^^^ RELAY

6.2" SERIES 2D, TYPE 150 DELCOTRON

Fig.
14c—Delcotrons - Full View

end or use Adapter J-21501 and a box wrench) on re-

taining nut, insert a 5/16" alien wrench through

socket and adapter into hex on shaft to hold the shaft

while removing the nut.

2.
Remove washer and slide pulley from shaft.

3.
To install, slide pulley and washer on shaft and start

the nut.

4.
Use the socket and adapter with a torque wrench and

tighten-nut to 50 ft. lbs. torque.

BRUSH
REPLACEMENT

6.2"
Delcotron

1.
Remove two nuts retaining the blade connectors and
remove the connectors (fig. 17c). Slide the indicator

light relay wire from the terminal post.

2.
Remove two screws retaining the capacitor and brush

holder to rear end frame, Remove brush holder.

3.
To install brushes, push brushes into holder and

install pin to keep the brushes in holder.

4.
Attach brush assembly and condenser to the end

frame with hex-head stud on the .left side only.

Fig.
15c—Pulley Removal

Fig.
16c—Torqulng Pulley Nut

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE-ELECTRICAL
6Y-16

POINT
OPENINGJL

Fig. 17c-6.2"
Brush
Holder
Assembly

5. Rearrange leads as shown in Figure 18c with right-

hand brush lead connected under the right hand hex-

head stud.

6. Remove pin and attach terminal cover with two

screws, making sure leads are not caught under-

neath the cover.

DOUBLE CONTACT REGULATOR

While most regular adjustments are made on the vehi-

cle as outlined under "Maintenance and Adjustments",

the regulator may be removed for field relay point and

air gap adjustment. However, voltage regulating contacts

should never be cleaned as they are made of special

material that may be destroyed by cleaning with any

abrasive material.

NOTE:
A sooty or discolored condition of the

contacts is normal after a relatively short

period of operation.
Fig. 19c—Checking Field Relay Point Opening

REMOVAL AND INSTALLATION

To remove the regulator assembly, disconnect the bat-

tery ground cable and the wiring harness connector at the

regulator, then remove the screws securing the regulator

to the vehicle.

Electrical settings must be checked and adjusted after

making mechanical adjustments. Before installing regu-

lator cover, make sure the rubber gasket is in place on

the regulator base.

MECHANICAL ADJUSTMENTS

NOTE:
Only an approximate voltage regulator

air gap setting should be made by the "feeler

gauge" method.

BRUSH

LEAD

BRUSH

LEAD
RELAY
^B-/lliLlK
CONDENSER

LEAD
GROUND
LEAD

STUD
AIR GAP

(Check
With
Points

Just
Touching)

Fig.
18c—Lead
Arrangement
after
Assembly
Fig. 20c—Checking Field Relay Air Gap

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE-ELECTRICAL 6Y-17

Field Relay Adjustment touching (fig. 20c). The air gap normally need not be

adjusted. If the point opening and closing voltages

1.
Point Opening: The point opening is checked as il- are within specifications, the relay will operate

lustrated in Figure 19c. If adjustment is necessary, satisfactorily even though the air gap may not be

carefully bend the armature stop. exactly according to specifications. If adjustment is

2.
Air Gap: Check the air gap with the points just necessary, bend the flat contact spring.

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE-ELECTRICAL 6Y-18

IGNITION SYSTEMS

INDEX

Page

General Description . 6Y-18

Maintenance and Adjustments 6Y-19

Breaker Point System 6Y-19

Breakerless System . . 6Y-X9

Ignition Coil Check 6Y-19

Spark Plugs 6Y-19

Service Operations , 6Y-19

Distributor Contact Points . 6Y-19

Cleaning 6Y-19

Replacement 6Y-20

Setting Dwell Angle 6Y-21

Distributor Condenser 6Y-22

Performance Diagnosis. 6Y-22

Replacement . . 6Y-23

Distributor

Breaker Point Type 6Y-23

Removal. . 6Y-23

Disassembly • 6Y-23
Page

Cleaning and Inspection .....'.., 6Y-25

Assembly . 6Y-25

Installation 6Y-26

Breakerless i 6Y-27

Removal . 6Y-27

Disassembly and Assembly 6Y-27

Installation 6Y-27

Off-Engine Test. . 6Y-27

Coil Replacement 6Y-27

Pulse Amplifier. 6Y-28

Disassembly .6Y-4S8

Component Checks
!
6Y-28

Assembly 6Y-29

Ignition Switch Replacement 6Y-29

Spark Plugs 6Y-30

Cleaning and Regapping I ....... 6Y-30

Installation . 6Y-31

GENERAL DESCRIPTION

There are two ignition systems available on 1967

vehicles. The breaker point type which is continued as

the regular production system and the optional (Corvette

only) transistor controlled breakerless ignition system

(magnetic pulse type). The transistor ignition system

features a specially designed distributor, control unit

(ignition pulse amplifier), and a special coil. Two resist-

ance wires are also used in the circuit; one as a ballast

between the coil negative terminal and ground, while the

other resistance wire provides a voltage drop for the

engine run circuit and is by-passed at cranking. The

other units in the system (the ignition switch, spark

plugs,
and battery) are of standard design. The dis-

tributor and control unit (ignition pulse amplifier) are

shown in Figures li and 2i.

CAP-

VACUUM

PICK-UP

COIL LEADS

PICK-UP COIL

CONNECTOR BODY
Although the external appearance of the distributor

resembles a standard distributor, the internal construc-

tion is quite different. As shown in the exploded view

(fig. 16i) an iron timer core replaces the conventional

breaker cam. The timer core has the same number of

equally-spaced projections, or vanes as engine cylinders.

The timer core rotates inside a magnetic pickup as-

sembly, which replaces the conventional breaker plate,

contact point set, and condenser assembly. The magnetic

pickup assembly consists of a ceramic permanent mag-

net, a pole piece, and a pickup coil. The pole piece
is.
a

steel plate having equally spaced internal teeth, one tooth

for each cylinder of the engine.

The magnetic pickup assembly is mounted over the

main bearing of the distributor housing, and is made to

rotate by the vacuum control unit, thus providing vacuum

advance. The timer core is made to rotate about the shaft

by conventional advance weights, thus providing centrifu-

gal advance.

Fig.
li—
Magnetic Pulse Distributor
Fig.
2i-lgnition Pulse Amplifier Unit

CHEVROLET CHASSIS SERVICE MANUAL

MAINTENANCE AND ADJUSTMENTS
ENGINE-ELECTRICAL 6Y-19

PERIODIC MAINTENANCE

BREAKER POINT SYSTEM

The distributor breaker points and spark plugs are the

only ignition system components that require periodic

service. The remainder of the ignition system requires

only periodic inspection to check operation of the units,

tightness of the electrical connections, and condition of

the wiring. When checking the coil, test with a reputable

tester.

Breaker type distributors are equipped with cam lubri-

cator and should have the wick replaced at the same time

contact point set is replaced. It is not necessary to

lubricate the breaker cam when using a cam lubricator.

Do not attempt to lubricate the wick - Replace when

necessary. When installing a new wick, adjust its posi-

tion so the end of the wick just touches the lobe of the

breaker cam.

Distributor shaft lubrication is accomplished by a

reservoir of lube around the mainshaft in the distributor

body.

BREAKERLESS SYSTEM

Since there are no moving parts in the ignition pulse

amplifier unit mounted forward of the radiator bulkhead,

and the distributor shaft and bushings have permanent

type lubrication, no periodic maintenance is therefore

required for the breakerless ignition system. The dis-

tributor lower bushing is lubricated by engine oil through

a splash hole in the distributor housing, and a housing

cavity next to the upper bushing contains a supply of

lubricant which will last between overhaul periods. At

time of overhaul, the upper bushing may be lubricated

by removing the plastic seal and then adding SAE 20 oil

to the packing in the cavity. A new plastic seal will be

required since the old one will be damaged during

removal.

Tachometer readings for test purposes can be made on

the primary circuit of the breakerless ignition system in

the same manner as on the conventional ignition system,

however before attempting to connect a test tachometer

into the primary circuit check with your instrument

supplier to insure that satisfactory readings can be

obtained and the breakerless system will not be damaged

by the tachometer that is to be used,

IGNITION COIL CHECK (BREAKERLESS)

The ignition coil primary can be checked for an open
PULSE

AMPLIFIER

IGN. SWITCH WIRE

"("IGN" TERMINAL)
-E3 IJU
12
WHITE-

-20 BLACKf' • 12 WHITE-

Fig.
3i—
Breakerless Ignition System

condition by connecting an ohmmeter across the two

primary terminals with the battery disconnected. Pri-

mary resistance at 75
°F.
should be between .35 and .55

ohm. An infinite reading indicates the primary is open.

For the engine to run but miss at times, the primary

open may be of the intermittent type.

The coil secondary can be checked for an open by con-

necting an ohmmeter from the high tension center tower

to either primary terminal. To obtain a reliable reading,

a scale on the ohmmeter having the 20,000 ohm value

within, or nearly within, the middle third of the scale

should be used. Secondary resistance at 75°F. should be

between
8,000
and 12,500 ohms. If the reading is infinite,

the coil secondary winding is open.

A number of different types of coil testers are avail-

able from various test equipment manufacturers. When

using these testers, follow the procedure recommended

by the tester manufacturer.

tester will properly
NOTE:
Make sure the

check this special coil.

SPARK PLUGS

Should be removed, inspected cleaned and regapped at

tune-up. Defective plugs should be replaced, see Servic-

ing of Units Off the Vehicle.

SERVICE OPERATIONS

DISTRIBUTOR CONTACT POINTS

CLEANING

Dirty contact points should be dressed with a few

strokes of a clean, fine-cut contact file. The file should

not be used for other metals and should not be allowed to

become greasy or dirty. Never use emery cloth to clean

contact points. Contact surfaces, after considerable use,

may not appear bright and smooth, but this is not neces-
sarily an indication that they are not functioning satis-

factorily. Do not attempt to remove all roughness nor

dress the point surfaces down smooth; merely remove

scale or dirt.

Badly burned or pitted contact points should be re-

placed and the cause of trouble determined so it can be

eliminated. High resistance or loose connections in the

condenser circuit, oil or foreign materials on the contact

surfaces, improper point adjustment or high voltages may

CHEVROLET CHASSIS SERVICE MANUAL