HEATER AND AIR CONDITIONING 1A-81
HORN RELAY
r
CONN.-
14 BROWN
(TO FUSE
PANEL)
BATTERY
1
—I ^ COMPR
ESSOR
DASH y
V-^ PANEL \
GROMMET—%
1 \
_ J~ ") "^
>14 BLACK/RED STRIPE-
FUSE .20 AMP.
•WIRE ASM. BLOWER-
MOTOR
14 BLACK 1
IGNITION SWITCH1
(ACCESSORY
TERMINAL)
CONTROL SWITCH
-RESISTOR
CONN.
•14 TAN
•16 BLACK
LIGHT BLUE STRIPE
•THERMOSTAT CONTROL
EVAPORATOR & BLOWER ASM.
Fig.
117—Universal System Wiring Diagram (Typical)
CHEVROLET CHASSI
HEATER AND AIR CONDITIONING 1A-82
•BATTERY
(POS)
CABLE
NOTE
When
control
switch*
is !TOFF"
&
Air
Cond
is
"ON"
(Control
knob
pulled
but) the
blower
fan'will
run at low
speed.
CONTROL
SWITCH
CONNECTIONS
OFF
LOW
MED
HIGH
B
TO
NONE
B
TO L
BTOL&M
B
TO L
&
H
COMPRESSOR
GROUND
WIRE
ASM
BATTERY
(NEGATIVE)
CABLE
COMPRESSOR
ASM
DASHPAJSTEL
GROMMET
16DG
CONTROL
SWITCH
RESISTOR
ASM
14LBL
14BRN
CLUTCH
COIL
EXTENSION
WIRE
ASM
-14BRN--N
JUNC
BLOCKi
OSTATIC
SWITCH
CONTACTS
NORMALLY
CLOSED
STARTING
MOTOR
SOLENOID
BLOWER
MOTOR
AIR
COND
CONTROL
(PUSH-PULL)
KNOB
DOOR
SWITCH
(PUSH
BUTTON
NORMALLY
CLOSED)
RELAY
ASM
HORN
RELAY
DIVERTER
DOOR CABLE
FUSE
PANEL
EVAPORATOR
ASM
IGNITION SWITCH-
ACCESSORY TERMINAL)
Fig. 118—All Weather Wiring Diagram (Chevy II)
CHEVROLET CHASSIS SERVICE MANUAL
HEATER AND AIR CONDITIONING 1A-83
DIVERTER DOOR
CRANK POSITIONS:
AIR COND "ON"
AIR COND "OFF*
AIR COND SWITCH
(PUSH BUTTON,
NORMALLY CLOSED
CONTACTS)
BLOWER MOTOR
CONTACTS
NORMALLY
4D
16
16B/Y
COMPRESSOR
GROUND WIRE
ASM
BAT.
TERMINAL
ON STARTING
MOTOR SOLENOID
' BATTERY
CABLE ASM:
NEGATIVE
POSITIVE—*
- CONTROL SWITCH
SET AT:
•OFF
LOW
MED
HIGH
CONTACTS:
BTOBL
BTOL
BTOM
BT0M6B,
CLUTCH
HOUSING
liOli: WHEN CONTROL
SWITCH IS AT "OFF" &
AIR COND. IS "ON", FAN
WILL RUN AT LOW SPEED.
"AIR COND-PULL"
KNOB (SHOWN IN "ON"
POSITION)
TO REGULATOR
HORN
RELAY
16 BRN-BODY WIRING
HARNESS-837
14BRN
I
^
IA^RN
* IGNITION SWITCH
« 12R ACCESSORY TERMINAL
12R f
AMMETER
LEGEND:
AIR COND WIRING (PART OF
ENGINE WIRING HARNESS)
WIRING IS PART OF EQUIP
REG PRODUCTION WIRING
Fig.
119—Corvette—Four-Season Wiring Diagram
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
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-11
I
BAT
JUNCTION BLOCK
DELCOTRON
—GRQ
BATTERY
&HJVVWV
0 VA OHM TEST RELAY >
RESISTOR [ 1 d
FUSIBLE
LINK
TO CRANKING
MOTOR
Ik
REGULATOR
VOLTMETER
FUSIBLE LINK
IGN.
SWITCH
Fig.
7c—Voltage Setting Test Connections
NOTE:
Voltage will not greatly exceed 12-1/2
volts until the battery develops a surface charge,
a few minutes generally, unless the battery is
severely discharged or is hot.
If reading is:
a. 12-1/2 volts or more, turn off electrical loads,
stop engine and proceed to Step 7.
b.
Less than 12-1/2 volts, perform "Delcotron Out-
put Test-Voltmeter Method."
(1) Delcotron tests bad—refer to "Service Op-
erations" and repair Delcotron, then repeat
Step 6.
(2) Delcotron tests good—disconnect regulator
connector, remove regulator cover and recon-
nect the connector. Then repeat Step 6 and
turn voltage adjusting screw (fig. 6c) to raise
setting to 12-1/2 volts. On transistor regula-
tor remove pipe plug (fig. 6c), insert screw
driver into slot and turn clockwise one or two
notches to increase setting. Turning counter-
clockwise decreases setting. For each notch
moved, the voltage setting will change ap-
proximately .3 volt. Turn off loads, stop en-
gine and proceed to Step 7. If 12-1/2 volts
cannot be obtained, install a new regulator and
repeat Step 6.
ADJUSTING REGULATOR VOLTAGE
7. Connect a 1/4 ohm-25 watt fixed resistor (purchased
commercially) into the charging circuit at the junc-
tion block as shown in Figure 7c.
NOTE:
Between both leads and the terminal.
8. Run engine at 1500 rpm or above for at least 15
minutes of warm-up, then cycle regulator voltage
control (by disconnecting and re-connecting regulator
connector) and read voltage.
If voltage is 13.5 to 15.2, the regulator is okay.
If voltage is not within 13.5 to 15.2 volts, leave en-
gine running at 1500 rpm or above and:
a. Disconnect four terminal connector and remove
regulator cover. Then re-connect four terminal
connector and adjust voltage to i4.2 to 14.6.
(Refer to Step 6 and fig. 6c).
b.
Disconnect four terminal connector and reinstall
regulator cover, then reinstall connector.
c. Continue running engine at 1500 rpm for 5-10
minutes to re-establish regulator internal
temperature.
d. Cycle regulator voltage by disconnecting and re-
connecting regulator connector. Read voltage. A
reading between 13.5 and 15.2 indicates a good
regulator.
CAUTION: Be sure four terminal regulator
connector is disconnected when removing or in-
stalling cover. This is to prevent regulator
damage by short circuits.
DELCOTRON OUTPUT TEST
Ammeter Method (Fig. 8c)
1.
Disconnect the battery ground cable at the battery.
2.
Disconnect the red wire at Delcotron battery termi-
nal and connect an ammeter in series between the
wire and terminal.
3.
Connect a voltmeter from battery terminal to a good
ground on the generator.
4.
Disconnect the F-R terminal connector at the
Delcotron.
5. Connect the jumper wire between Delcotron "F" and
battery terminals.
6. Connect the battery ground cable at the battery.
7. Connect an adjustable carbon pile across the battery
posts.
8. Start the engine and slowly bring the speed to 1500
RPM and at the same time adjust the carbon pile
load to hold the voltage at 14 volts.
9. Read the amperage and compare with a specifications
chart.
CHEVROLET CHASSIS SERVICE MANUAL