1993 CHEVROLET DYNASTY charging

SERVICE PROCEDURES INDEX
page page
Automatic Transmission Oil Coolers .......... 23
Coolant ................................ 14
Coolant Recovery System (CRS) ............. 17
Cooling System Drain, Clean, Flush and Refill . . 15
Electric Fan Motor ........................ 22
Engine Thermostats ....................... 13
Fan Shroud ............................. 23 Fans
.................................. 21
Radiator Hoses .......................... 21
Radiator Pressure Cap .................... 18
Radiators ............................... 18
Testing System for Leaks .................. 17
Water Pumps ........................... 10
WATER PUMPS
A quick test to tell whether or not the pump is
working is to see if the heater warms properly. A
defective pump will not be able to circulate heated
coolant through the long heater hose. The water pump on all models can be replaced
without discharging the air conditioning system.
WATER PUMPÐ2.2/2.5L ENGINE
The 2.2/2.5L engine water pump has a diecast alu-
minum body and housing with a stamped steel impel-
ler. The 2.2/2.5L pump uses an O-ring gasket between
body and housing. The assembly bolts directly to the
block. Cylinder block to water pump sealing is provided
by a rubber O-ring.
REMOVAL (1) Drain cooling system. Refer to Draining Cooling
System in this group. (2) If equipped with air conditioning, see Solid
Mount Accessory Bracket in (Standard Service Proce-
dures) Group 9, Engine: (a) Remove air conditioning compressor and gen-
erator from solid mount bracket and set aside.It is
not necessary to discharge the a/c system. (b) Remove solid mount bracket.
(3) If the vehicle is not equipped with air condi-
tioning, remove generator and mounting bracket. (4) Disconnect lower radiator and heater hoses
from pump. (5) Remove water pump attaching screws to engine
(Fig. 1). Turbo III has a spacer between the water
pump and block on the lower screw.
DISASSEMBLY (1) Remove three screws holding pulley to water
pump. (2) Remove nine screws holding water pump body
to housing. Remove the pump body from housing
(Fig. 2). (3) Clean gasket surfaces on water pump housing
and engine block. (4) Remove and discard O-ring gaskets and clean
O-ring grooves.
Fig. 2 Water Pump ComponentsÐ2.2/2.5L
Fig. 1 Water PumpÐ2.2/2.5L Engines
7 - 10 COOLING SYSTEM Ä

sends the message to the Engine Controller. The En-
gine Controller turns on the fan through the fan re-
lay. See Wiring Diagrams Manual for circuity and
diagnostics provided.Switching through the Engine Controller provides
fan control for the following conditions.
² The fan will not run during cranking until the en-
gine starts no matter what the coolant temperature
is.
² Fan will run when the air conditioning clutch is
engaged and low pressure cutout switch is closed.
² For 4 cylinder application the fan will run at ve-
hicle speeds above about 40 mph only if coolant tem-
perature reaches 110ÉC (230ÉF). It will turn off when
the temperature drops to 104ÉC (220ÉF). At speeds
below 40 mph the fan switches on at 102ÉC (215ÉF)
and off at 93ÉC (200ÉF).
² This is to help prevent steaming. The fan will run
only below 16ÉC (60ÉF) ambient. Between 38ÉC
(100ÉF) to 97ÉC (195ÉF) coolant temperature, at idle
and then only for three minutes.
RADIATOR FAN CONTROLÐAC/AY BODY V-6 ONLY
For this application, fan control is accomplished
based on coolant temperature, and on A/C head pres-
sure. These vehicles receive the variable displace-
ment compressor. The fan will go on when;
² Coolant temperature reaches 102ÉC (215ÉF) and off
at 93.4ÉC (200ÉF) regardless of vehicle speed.
² When the head pressure reaches 1516.9 kPa (220
psi) and turn off when the pressure reaches 1103 kPa
(160 psi).
TEMPERATURE GAUGE INDICATION
At idle the temperature gauge will rise slowly to
about 5/8 gauge travel. The fan will come on and the
gauge will drop to about 1/2 gauge travel, this is nor-
mal.
ELECTRIC FAN MOTOR
To check out the electric fan motor, disconnect the
fan motor wire connector and connect it with #14
gauge wires to a good 12-volt battery observing cor-
rect polarity per (Fig. 14). If the fan runs normally,
the motor is functioning properly. If not, replace fan
module using the removal and installation instruc-
tions contained in the Fan Section. If the motor is
noticeably overheated (i.e.; wire insulation melted,
motor charred) the system voltage may be too high.
Check charging system, see Group 8A, Battery/Start-
ing/Charging System Diagnostics.
ELECTRIC FAN MOTOR TEST
Equipment required
² Diagnostic Tool DRB II or equivalent
² Volt/Ohm Meter
² Wiring Diagram Manual (1) Run the engine to normal operating tempera-
ture. (2) Check wiring connector in C25, C9, and C26 for
proper engagement, see Wiring Diagram Manual (3) Using a diagnostic tool, plugged into the diag-
nostic connector rearward of the battery, check the
On-Board Diagnostics (OBD) in the Engine Control-
ler for fault codes, see Group 14, Fuel Injection for
instructions. (4) If fault code 88-12-35-55 is detected, proceed to
Step 5. (5) With the ignition switch in the run position,
test for battery voltage (single pin connector) at the
fan relay. Voltage reading OK, proceed to Step 6a.
Voltage at 0-1 volt, proceed to Step 6b. 6(a) With the ignition off, disconnect the 60-way
connector from the Engine Controller (outboard of
battery) and return the ignition to the run position.
Test for battery voltage at cavity 31 of the 60-way
connector (Fig. 15). Voltage reading OK and female
terminal is not damaged, replace the Engine Control-
ler. Voltage reading 0, repair open or short in C27
circuit. (b) With the ignition off, disconnect the 60-way
connector from the Engine Controller (outboard of
battery) and return the ignition to the run position.
Test for battery voltage at the single pin connector
at the fan relay. Voltage reading OK, replace the
Engine Controller. Voltage reading 0-1 volt, pro-
ceed to Step 7.
(7) With ignition in the run position, test for bat-
tery voltage at the wire (C27) in the 3-way connector
of the fan relay. Voltage reading OK, replace the fan
relay. Voltage reading 0, repair open or short in C27
circuit. (8) Turn ignition off, connect the 60-way connector
at the Engine Controller and test the system.
Fig. 14 Electric Fan MotorÐTypical
7 - 22 COOLING SYSTEM Ä

BATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICS
CONTENTS
page page
BATTERY TEST PROCEDURES ON-VEHICLE . . 3
FAULT CODESÐON BOARD DIAGNOSTICS . . 23
GENERAL INFORMATION .................. 1
GENERATOR TEST PROCEDURES ON VEHICLE.19 IGNITION OFF DRAW (IOD)
............... 9
SPECIFICATIONS ....................... 28
STARTER TEST PROCEDURES ON VEHICLE . 11
GENERAL INFORMATION
² For Battery, Starter or Generator replacement re-
fer to Group 8B, Battery/Starter/Generator Service.
This Group 8A will cover diagnostics only. The Battery, Starting, and Charging Systems oper-
ate with one another, and must be thoroughly tested
as a complete system. To enable the vehicle to start
and charge properly, it must have a battery that will
perform to specifications. The starter motor, genera-
tor, wiring, and electronics also must perform within
specifications. Group 8A will cover Starting (Fig. 1)
and Charging System (Fig. 2) diagnostic procedures.
These will be covered from the most basic conven-
tional methods to On Board Diagnostics (OBD) built
into the vehicle's electronics. The need for conven-
tional testing equipment has not been eliminated by
the introduction of OBD. Frequent use of an amme-
ter, volt/ohmmeter, battery charger, carbon pile rheo-
stat (load tester), and 12 volt (low wattage) test light
will be required. All front wheel drive vehicles are equipped with
OBD and all OBD sensing systems are monitored by
the Powertrain Control Module. The Powertrain Con-
trol module will store in electronic memory, any de-
tectable failure within the monitored circuits. It will
retain this information for a period of 50 engine
starts, then erase the memory if the failure does not
reoccur during that period. This also will translate a
monitored failure as a FAULT CODE when a read-
out command is given. A readout command can be
made by turning the ignition switch to ON-OFF-ON-
OFF-ON without starting the engine. The Malfunc-
tion Indicator (CHECK ENGINE) Lamp on the
instrument cluster will flash in preset sequences to
show Fault Codes. However, the Malfunction Indica-
tor (Check Engine) Lamp cannot express fault codes
for all failures. Fault codes are easier to obtain and
more complete with the use of Diagnostic Tool (DRB
II). This tool is plugged into the diagnostic connector located in the engine compartment (Fig. 2). Refer to
the instructions provided with the (DRB II) tool be-
ing used. For numbered Fault Codes pertaining to compo-
nents within this Group, refer to Failure CodesÐOn
Board Diagnostics in Group 8A. For other Fault
Codes which, do not pertaining to this Group 8A, re-
fer to Group 14, Fuel System, On Board Diagnostics.
Fig. 1 Starting System Components
Ä BATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICS 8A - 1

Fig. 2 Charging System Components
8A - 2 BATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICS Ä

BATTERY TEST PROCEDURES ON-VEHICLE INDEX
page page
Battery Charging .......................... 7
Battery Load Test ......................... 6
Battery Open Circuit Voltage Test ............. 4
Causes of Battery Discharging ............... 4 General Information
........................ 3
State of Charge Tests ...................... 4
Test Indicator ............................ 3
GENERAL INFORMATION
The battery stores, stabilizes, and produces electri-
cal current to operate various electrical systems in
the vehicle. The determination of whether a battery
is good or bad is made by the battery's ability to ac-
cept a charge. It also must produce high amperage
current output over an extended period to be able to
start the vehicle. The capability of the battery to
store electrical current comes from a chemical reac-
tion. This reaction takes place between the sulfuric
acid solution electrolyte and the lead +/- plates in
each cell of the battery. As the battery discharges,
the plates react with the acid from the electrolyte.
When the charging system charges the battery, the
water is converted to sulfuric acid in the battery. The
amount of acid, specific gravity in the electrolyte can
be measured with a hydrometer. The factory in-
stalled battery is equipped with a built in hydrome-
ter as a test indicator (Figs. 3, 4 and 5) to help in
determining the battery's state of charge. The factory
installed battery also is sealed. Water cannot and
should not be added.
The battery is vented to release gases that is cre-
ated when the battery is being charged and dis-
charged. The battery top, posts, and terminals should
be cleaned when other under hood maintenance is
performed (Fig. 3).
WARNING: DO NOT ASSIST BOOST, CHARGE, ADD
WATER, OR LOAD TEST BATTERY WHEN ELEC- TROLYTE LEVEL IS BELOW THE TOP OF THE
PLATES. PERSONAL INJURY MAY OCCUR.
When the electrolyte level is below the top of the
plates a yellow or bright color indicator in sight glass
(Figs. 4 and 5), the battery must be replaced. Refer
to Test Indicator. The battery must be completely
charged with a green color in sight glass. The top,
posts, and terminals should be properly cleaned be-
fore diagnostic procedures are performed. Also refer
to Group 8B, Battery/Starter/Generator Service.
TEST INDICATOR
The test indicator a hydrometer is viewed through
a sight glass, it is built into the top of battery case
(Figs. 3, 4 and 5). This provides visual information
for battery testing. The test indicator sight glass is to
be used with diagnostic procedures described in this
Group.
Fig. 3 Battery Construction and Test Indicator
Fig. 4 Built in Test Indicator
Fig. 5 Test Indicator Sight Glass
Ä BATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICS 8A - 3

It is important when using the Test Indicator that
the battery be level and have a clean top to see the
correct indications. A light may be required to view
the Indicator.
WARNING: DO NOT USE OPEN FLAME NEAR BAT-
TERY BECAUSE OF EXPLOSIVE GASES AT FORM
ABOVE BATTERY.
STATE OF CHARGE TESTS
USING TEST INDICATOR
The built in test hydrometer (Figs. 3, 4 and 5) mea-
sures the specific gravity of the electrolyte. Specific
Gravity (SG) of the electrolyte will show state of
charge voltage. The test indicator WILL NOT show
cranking capacity of the battery. Refer to Battery
Load. Look into the sight glass (Figs. 4 and 5) and
note the color of the indicator (Fig. 5). Refer to the
following description of colors:
² GREEN = 75 to 100 degree state of charge
The battery is adequately charged for further test-
ing and may be returned to use. If the vehicle will
not crank for a maximum 15 seconds, refer to Bat-
tery Load Test in this Group for more information.
² BLACK OR DAR K=0to75degree state of
charge The battery is INADEQUATELY charged and
must be charged until green dot is visible, (12.4 volts
or greater) before the battery is tested or returned to
use. Refer to Causes of Battery Discharging.
² YELLOW OR BRIGHT COLOR = Battery must
be replace
WARNING: DO NOT CHARGE, ASSIST BOOST,
LOAD TEST, OR ADD WATER TO THE BATTERY
WHEN YELLOW OR BRIGHT COLOR DOT IS VISI-
BLE. PERSONAL INJURY MAY OCCUR.
A yellow or bright color dot shows electrolyte level
in battery is below the test indicator (Fig. 5). Water
cannot be added to a maintenance free battery. The
battery must be replaced. A low electrolyte level may
be caused by an over charging condition. Refer to
Generator Test Procedures on Vehicle.
CAUSES OF BATTERY DISCHARGING
It is normal to have a small 5 to 30 milliamperes
continuous electrical draw from the battery. This
draw will take place with the ignition in the OFF po-
sition, and the courtesy, dome, storage compart-
ments, and engine compartment lights OFF. The
continuous draw is due to various electronic features
or accessories that require electrical current with the
ignition OFF to function properly. When a vehicle is
not used over an extended period approximately 20
days the Main Fusible Link Connector (Fig. 6)
should be disconnected. This is located near the bat- tery on the engine wiring harness. Disconnection of
this connector will help prevent battery discharging.
Refer to Fig. 7 for Battery Diagnostics.
ABNORMAL BATTERY DISCHARGING
(1) Corroded battery posts, cables or terminals.
(2) Loose or worn generator drive belt.
(3) Electrical loads that exceed the output of the
charging system due to equipment or accessories in-
stalled after delivery. (4) Slow driving speeds in heavy traffic conditions
or prolonged idling with high-amperage electrical
systems in use. (5) Defective electrical circuit or component caus-
ing excess Ignition Off Draw (IOD). Refer to Ignition
OFF Draw (IOD). (6) Defective charging system.
(7) Defective battery.
BATTERY OPEN CIRCUIT VOLTAGE TEST
An open circuit voltage, no load test will show the
state of charge in a battery. Also, if it will pass a
load test of 50 percent of the battery cold crank rat-
ing. Refer to Battery Load Test. If a battery has an
open circuit voltage reading of 12.4 volts or greater,
and will not pass a load test, it is defective and re-
placement would be required. To test open circuit
voltage, perform the following operation: (1) Remove both battery cables, negative first. If
the battery has been boosted, charged, or loaded just
prior to this operation, allow the battery a few min-
utes to stabilize. (2) Using a voltmeter connected to the battery
posts and measure the open circuit voltage (Fig. 8).
Fig. 6 Main Fusible Link Connector
8A - 4 BATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICS Ä

Fig. 7 Battery Diagnostics
Ä BATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICS 8A - 5

This voltage reading will show the battery state of
charge. It will not reveal battery cranking capacity
(Fig. 8).
BATTERY LOAD TEST
A fully charged battery must have reserve crank-
ing capacity. This will enable the starter motor and
ignition system enough power to start the engine
over a broad range of ambient temperatures. A bat-
tery load test will verify the actual cranking perfor-
mance based on the cold crank rating of the battery.
WARNING: IF BATTERY SHOWS SIGNS OF FREEZ-
ING, LEAKING, LOOSE POSTS, OR EXCESSIVELY
LOW ELECTROLYTE LEVEL, DO NOT TEST. ACID
BURNS OR AN EXPLOSIVE CONDITION MAY RE-
SULT. (1) Remove both battery cables, negative first. Bat-
tery top, cables and posts should be clean. If green
dot is not visible in indicator, charge the battery. Re-
fer to Battery Charging Procedures. (2) Use a suitable Volt Ammeter Load tester (Fig.
10) connected to the battery posts (Fig. 11). Check
the open circuit voltage of the battery. Voltage should be equal to or greater than 12.4
volts with the green dot visible in test indicator. (3) Rotate the load control knob Carbon pile rheo-
stat to apply a 300 amp load. Apply this load for 15 seconds to remove the surface charge from the bat-
tery, and return the control knob to off (Fig. 12).
(4) Allow the battery to stabilize for 15 seconds,
and then verify open circuit voltage. (5) Rotate the load control knob on the tester to
maintain 50 percent of the battery cold crank rating
for a minimum 15 seconds (Fig. 13).
Fig. 8 Testing Open Circuit Voltage
Fig. 9 Battery Open Circuit Voltage
Fig. 10 Volt-Ammeter-Load Tester
Fig. 11 Volt-Ammeter-Load Tester Connections
Fig. 12 Remove Surface Charge from Battery
8A - 6 BATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICS Ä