1993 CHEVROLET DYNASTY engine

GENERATOR TEST PROCEDURES ON VEHICLE INDEX
page page
Charging System Diagnostics (Fig. 1) ......... 19
Current Output Test ...................... 19 Output Wire Resistance Test
................ 19
CHARGING SYSTEM DIAGNOSTICS (Fig. 1)
OUTPUT WIRE RESISTANCE TEST
The generator output wire resistance test shows
the amount of voltage drop across the generator out-
put wire between the generator B+ terminal and the
positive battery post.
PREPARATION
Before starting test, make sure the vehicle has a
fully charged battery. Tests and procedures to check
for a fully charged battery is shown in the Battery
section. (1) Turn the ignition switch OFF.
(2) Disconnect battery NEGATIVE cable.
(3) Disconnect the generator B+ output wire from
the generator output battery terminal (Fig. 2). (4) Connect a 0-150 ampere scale (DC) ammeter in
series between B+ terminal and output wire (Fig. 2
and 3). Connect positive lead to B+ terminal, and
negative lead to output wire. (5) Using o-18 volt scale voltmeter, connect the
positive lead to the disconnected (B+) output wire
(Fig. 2). Connect the negative lead to positive battery
post. (6) Remove fresh air hose between Powertrain
Control Module and air cleaner if necessary. (7) Connect jumper wire between a good ground
and K20 circuit terminal at the back of the genera-
tor.
CAUTION: Do not connect the A142 circuit terminal
(Fig. 2) to ground the Fusible link will burn.
(8) Connect an engine tachometer and connect bat-
tery negative cable. (10) Connect a volt/amp tester equipped with a
variable carbon pile rheostat between battery termi-
nals (Fig. 4).
Caution: Be sure the carbon pile is in OFF position
before connecting leads.
TEST
(1) Start engine. Immediately after starting, re-
duce engine speed to idle. (2) Adjust engine speed and carbon pile to main-
tain 20 amperes flowing in the circuit. Observe volt-
meter reading. Voltmeter reading should not exceed
0.5 volts.
RESULTS
If a higher voltage drop is shown, inspect, clean
and tighten all connections between generator B+
terminal and battery positive post. A voltage drop
test may be performed at each connection to locate a
connection with excessive resistance. If resistance
tests are satisfactory, reduce engine speed, turn off
carbon pile, and turn off ignition switch. (1) Disconnect battery negative cable.
(2) Remove test ammeter, voltmeter, carbon pile,
and tachometer. (3) Remove jumper wire.
(4) Connect generator output wire to generator B+
terminal. (5) Connect battery negative cable.
(6) Connect fresh air hose between Powertrain
Control Module and air cleaner if removed.
CURRENT OUTPUT TEST
The current output test decides whether the gener-
ator can deliver its rated current output. For gener-
ator identification and output amperage
specifications, refer to Generator Specifications. For generator maximum voltage at individual tem-
peratures, refer to Generator Output Voltage Specifi-
cations.
PREPARATION
Before starting any tests, make sure the vehicle
has a fully charged battery. Tests and procedures to
check for a fully charged battery is shown in Battery
section. (1) Disconnect battery negative cable.
(2) Disconnect output wire at the B+ terminal
(Figs. 2 and 5). (3) Connect a 0-150 ampere scale (DC) ammeter in
series between the B+ terminal and output wire.
Connect Positive lead to B+ terminal and negative
lead to output wire. (4) Using 0-18 voltmeter, connect positive lead to
B+ terminal (Figs. 2 and 5). Connect negative lead
to a good ground.
Ä BATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICS 8A - 19

(5) Connect an engine tachometer and connect bat-
tery negative cable. (6) Connect a volt/amp tester equipped with a vari-
able carbon pile rheostat between battery terminals
(Fig. 6). Be sure carbon pile is in OFF position before
connecting leads. (7) Remove fresh air hose between Powertrain
Control Module computer and air cleaner if neces-
sary. (8) Full field the generator. Connect a jumper wire
between a good ground and K20 circuit terminal at
the back of the generator (Figs. 2 and 5).
CAUTION: Do not connect the A142 circuit terminal
(Fig. 2) to ground. Fusible link will burn.
TEST
(1) Start the engine. Immediately after starting,
reduce engine speed to idle.
Fig. 2 Generator Wiring Connections
Fig. 3 Generator Output Wire Resistance Test
Fig. 4 Volt/Amp Tester Connections
Ä BATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICS 8A - 21

(2) Adjust the carbon pile and engine speed in
steps until an engine speed of 1250 rpm, and a volt-
meter reading of 15 volts is obtained.
CAUTION: Do not allow the battery voltage to ex-
ceed 16 volts. (3) The generator amperage must meet the output
requirements for the particular generator being
tested. Refer to Generator Specifications for genera-
tor identification and amperage outputs.
RESULTS
(1) If amperage reading is less than specified, and
generator output wire resistance is not found exces-
sive from the previous tests, generator should be re-
placed. Refer to Group 8B, Battery/Starter/Generator
Service, Generator Replacement. These generators
are not intended to be disassembled for service. It
must be replaced as an assembly. (2) After current output test is completed, reduce
engine speed, turn off carbon pile, and turn off igni-
tion switch. (3) Disconnect battery negative cable.
(4) Remove test ammeter, voltmeter, tachometer
and carbon pile. (5) Remove jumper wire between K20 circuit ter-
minal and ground. (6) Connect output wire to B+ terminal.
(7) Connect negative battery cable.
(8) Connect fresh air hose between powertrain con-
trol module and air cleaner if removed.
Fig. 5 Generator Current Output Test
Fig. 6 Volt/Amp Tester Connections
8A - 22 BATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICS Ä

FAULT CODESÐON BOARD DIAGNOSTICS INDEX
page page
Diagnostic Testing Using Fault Codes ......... 24
Drb II Diagnostic Tester ................... 24 General Description/Information
.............. 23
GENERAL DESCRIPTION/INFORMATION
Another way of diagnosing charging system prob-
lems can be accomplished using the On Board Diag-
nostic System Fault Codes. A Fault Code shows a potential problem in a mon-
itored circuit, or a condition caused by a faulty component. A
Fault Code can be retrieved by turning the ignition
switch ON-OFF-ON-OFF-ON without starting the
engine, and counting the number of flashes of the
Malfunction Indicator (CHECK ENGINE) Lamp in
the instrument cluster.
EXAMPLES:
² If the Malfunction Indicator (Check Engine) Lamp
flashes four times, pauses, and flashes one more
time, a Code 41 is shown. The first set of four flashes
indicates number four. The second set of one flash in-
dicates one.
² If the Malfunction Indicator (Check Engine) Lamp
flashes four times, pauses, and flashes six more
times, a Code 46 is shown. The first set of four
flashes indicates number four. The second set of six
flashes indicates six.
² If the Malfunction Indication (Check Engine)
Lamp flashes four times, pauses, and flashes seven
more times, a Code 47 is shown. The first set of four
flashes indicates number four. The second set of
seven flashes indicates seven. POWERTRAIN CONTROL MODULE
The Powertrain Control Module is equipped with
On Board Diagnostic features and monitors all en-
gine control circuits during a run/drive period. If a
circuit or system does not perform properly, the pow-
ertrain control module will file in memory a preset
Fault Code. This can be used to help in diagnosing a
problem. After 50 to 100 ignition switch ON/RUN cy-
cles, the memory will be erased if the fault does not
reoccur. The Powertrain Control Module is located in the
engine compartment outboard of the battery (Fig. 7).
Refer to Fig. 8 Generator Fault Codes Chart for re-
lationships of generator/charging system Fault Code
numbers.
Fig. 7 Powertrain Control Module
Ä BATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICS 8A - 23

STARTER INDEX
page page
General Information ........................ 4
Neutral Starter and Back-Up Switch ........... 8
Starter Component Replacement .............. 5
Starter Interlock Switch: Clutch Pedal Mounted/ Manual Transmission Only ................. 7 Starter Motor Replacement
.................. 4
Starting System ........................... 4
Supply Circuit and Control Circuit ............. 4
GENERAL INFORMATION
This section will cover Starter replacement and
service procedures only. For starter diagnostic proce-
dures, refer to Group 8A, Battery/Starting/Charging
Systems Diagnostics.
STARTING SYSTEM
The starting system has:
² Ignition switch
² Starter relay
² Neutral starting and back-up switch with auto-
matic transmissions
² Clutch pedal mounted starter interlock switch
with manual transmissions
² Wiring harness
² Battery
² Starter motor with an integral solenoid
BOSCH STARTERS
²A Bosch permanent magnet starter motor is avail-
able on 2.2L, 2.5L and 3.0L engines on all vehicles.
A planetary gear train transmits power between
starter motor and pinion shaft. The fields consist of
six permanent magnets.
NIPPONDENSO STARTERS
² A Nippondenso reduction gear-field coil starter
motor is available on 3.0L, 3.3L and 3.8L engines.
SUPPLY CIRCUIT AND CONTROL CIRCUIT
Both starter systems consist of two separate cir-
cuits:
² A high amperage supply to feed the starter motor.
² A low amperage circuit to control the starter sole-
noid. For additional information on starter motor supply
and control circuits, refer to Group 8A, Battery/Start-
ing/Charging Systems Diagnostics.
STARTER MOTOR REPLACEMENT
BOSCH STARTERÐ2.2L/2.5L ENGINE
(1) Disconnect battery negative cable (Fig. 1).
(2) Raise vehicle. (3) Remove heat shield clip from the starter and
heat shield is clipped to starter (Fig. 2). For easier
servicing, do not remove the wiring from starter at
this time.
(4) Remove two bolts and one nut attaching starter
to engine (Fig. 3). (5) Remove starter/starter solenoid assembly from
engine. Position the starter to gain access to the wir-
ing connectors. (6) Disconnect the positive battery cable and wir-
ing at the starter. (7) Remove the starter from vehicle.
Fig. 1 Remove or Install Battery Cable
Fig. 2 Starter Heat ShieldÐ4 Cylinder Engines
8B - 4 BATTERY/STARTER/GENERATOR SERVICE Ä

(8) For installation, reverse above procedures.
Clean corrosion/dirt from the cable and wire termi-
nals before installing wiring to the solenoid.
BOSCH OR NIPPONDENSO STARTERÐ3.0L/ 3.3L/3.8L ENGINE
(1) Disconnect NEGATIVE battery cable (Fig. 1).
(2) Raise vehicle.
(3) Remove three starter attaching bolts at engine/
transaxle (Fig. 4).
(4) Remove the two wire connector terminal nuts
and remove wiring connector (Bosch, Fig. 5) (Nippon-
denso, Fig. 6 or 7). (5) Remove starter from vehicle (Bosch, Fig. 8)
(Nippondenso, Fig. 9). (6) For installation, reverse above procedures.
Clean corrosion/dirt from the cable and wire termi-
nals before installing wiring to the solenoid.
STARTER COMPONENT REPLACEMENT
Caution: When servicing the starter assembly off
the vehicle, do not clamp the starter to a vice. In-
ternal damage may result.
Fig. 3 Bosch StarterÐ2.2L/2.5L Engine
Fig. 4 Remove or Install Attaching BoltsÐTypical
Fig. 5 Wire Terminal ConnectionsÐBosch Starter
Fig. 6 Wire Terminal ConnectionsÐ3.0L EngineÐNippondenso Starter
Fig. 7 Wire Terminal ConnectionsÐ3.3L/3.8L EngineÐNippondenso Starter
Ä BATTERY/STARTER/GENERATOR SERVICE 8B - 5

GENERATOR INDEX
page page
General Information ........................ 9
Generator ReplacementÐ2.2L Turbo Engine (With 16 Valve Cylinder Head) ............. 10 Generator ReplacementÐ2.2L/2.5L Engine
...... 9
Generator ReplacementÐ3.0L Engine ......... 10
Generator ReplacementÐ3.3L/3.8L Engine ..... 11
GENERAL INFORMATION
This section will cover generator removal and instal-
lation only. Information covering generator on-vehicle
testing and diagnosis can be found in Group 8A,
Battery/Starting/Charging Systems Diagnostics. To
identify the generator, refer to the Generator Specifi-
cation chart at the rear of this section. These generators are not intended to be disas-
sembled for service. It must be replaced as an
assembly.
GENERATOR REPLACEMENTÐ2.2L/2.5L ENGINE
Removal and repositioning of A/C compressor (with-
out disconnecting refrigerant lines) is necessary on
some models to gain access to generator. (1) Disconnect battery negative cable (Fig. 1).
(2) If Equipped With Air Conditioning:
(a) Remove the A/C drive belt. Refer to Group 7,
Cooling System. (b) Remove the four bolts retaining the A/C com-
pressor to the mounting bracket (Fig. 2). (c) Without disconnecting the A/C refrigerant
lines, position the A/C compressor to allow generator
removal.
WARNING: THE A/C REFRIGERANT SYSTEM IS UN-
DER PRESSURE EVEN WHEN THE ENGINE IS OFF.
REFER TO THE SAFETY PRECAUTIONS AND WARN-
INGS SECTION IN HEATING AND A/C, GROUP 24,
BEFORE PERFORMING ANY SERVICE OPERATION. (3) Remove the generator drive belt. Refer to Group
7, Cooling System. (4) Remove the two generator mounting bolts (Fig.
3) and position the generator to gain access to all the
wire connectors. If equipped with:
² BOSCH GENERATOR: Remove B+ terminal nut,
field terminal nuts, and ground harness hold down
nuts (Fig. 4). Remove wire connector assembly.
² NIPPONDENSO GENERATOR: Remove nuts
from field terminals, ground terminal, wire harness
Fig. 1 Remove Battery Negative (-) Cable
Fig. 2 A/C Compressor ReplacementÐ2.2 L/2.5 L Engine
Fig. 3 Remove/Install Generator
Ä BATTERY/STARTER/GENERATOR SERVICE 8B - 9

and B+ terminal (Fig. 5). B+ terminal nut must be
removed last to prevent damage to terminal insula-
tor. (5) Remove the generator from the vehicle.
(6) For installation, reverse above procedures.
Tighten all fasteners to the proper torque. Refer to
the Torque Specifications chart at the rear of this
group.
GENERATOR REPLACEMENTÐ2.2L TURBO
ENGINE (WITH 16 VALVE CYLINDER HEAD)
(1) Disconnect battery NEGATIVE cable (Fig. 1).
(2) Remove generator/air conditioning drive belt.
Refer to Group 7, Cooling System. (3) Remove the bolts retaining the A/C compressor
to the mounting bracket. (4) Without disconnecting the A/C refrigerant
lines, position the A/C compressor to allow generator
removal. WARNING: THE A/C REFRIGERANT SYSTEM IS UN-
DER PRESSURE EVEN WHEN THE ENGINE IS OFF.
REFER TO THE SAFETY PRECAUTIONS AND
WARNINGS SECTION IN HEATING AND A/C,
GROUP 24, BEFORE PERFORMING ANY SERVICE
OPERATION.
(5) Remove the generator mounting bracket bolts
and separate generator from mounting bracket (Fig.
6).
(6) Remove the B+ terminal nut, field terminal
nuts, and ground/wire harness hold-down nuts. Re-
move wire connectors. (7) Remove the generator from the vehicle.
(8) For installation, reverse above procedures.
Tighten all fasteners to the proper torque. Refer to
the Torque Specifications chart at the rear of this
group.
GENERATOR REPLACEMENTÐ3.0L ENGINE
(1) Disconnect battery negative cable (Fig. 1).
(2) Remove generator drive belt. Refer to Group 7,
Cooling System. (3) Remove the generator mounting bolts and sep-
arate the generator from the mounting bracket (Fig.
7). (4) Remove the B+ terminal nut, field terminal
nuts, and ground/wire harness hold-down nuts. Re-
move wire connectors. (5) Remove the generator from the vehicle.
Fig. 4 Remove or Install Wire Connector AssemblyÐBosch Generator
Fig. 5 Remove or Install Wire ConnectorAssemblyÐNippondenso Generator
Fig. 6 Generator MountingÐ2.2 L Turbo Engine With 16 Valve Cylinder Head
8B - 10 BATTERY/STARTER/GENERATOR SERVICE Ä