light CHEVROLET DYNASTY 1993 Repair Manual

(3) Remove battery tray access cover (Fig. 3) from
battery tray. Do not discard, access cover MUST be
put back on battery tray, when battery is rein-
stalled.
(4) If equipped, remove the 2 bolts (Fig. 4) attaching
speed control vacuum reservoir to battery tray. Then
remove speed control vacuum reservoir (Fig. 4) from
the battery tray. Vacuum lines (Fig. 4) do not need
to be removed from vacuum reservoir. (5) Remove the 4 bolts attaching battery tray (Fig. 5)
to frame rail and fender shield of vehicle. Then remove
battery tray from vehicle. (6) Remove battery acid shield, (Fig. 6) from the ABS
modulator assembly. (7) Remove brake tube from the proportioning valve,
requiring removal from modulator assembly (Fig. 7). (8) Remove proportioning valve (Fig. 7) requiring
replacement from the modulator assembly. INSTALL
(1) Slightly moisten proportioning valve to modulator
assembly sealing O-Ring with fresh clean brake fluid.
(2) Install proportioning valve into modulator as-
sembly by hand, until O-Ring seal is fully seated
Fig. 4 Speed Control System Vacuum Reservoir
Fig. 5 Battery Tray And Attaching Bolts
Fig. 6 ABS Modulator Assembly Acid Shield
Fig. 2 Battery Heat Shield And Hold Down Clamp
Fig. 3 Battery Tray Shield
Ä ANTILOCK 4 BRAKE SYSTEM 5 - 39

MANUAL TRANSAXLE CLUTCH
CONTENTS
page page
CLEANING PRECAUTIONS ................. 6
CLUTCH CABLE MECHANISM .............. 1
CLUTCH CABLE REPLACEMENT ............ 2
CLUTCH CHATTER COMPLAINTS ........... 1
CLUTCH DISC REPLACEMENT ............. 5
CLUTCH PEDAL NOISE/POP ............... 2 CLUTCH PEDAL POSITION SWITCH
......... 4
EXCESSIVE CLUTCH SPIN TIME/CLASH INTO REVERSE COMPLAINTS ............ 1
GENERAL INFORMATION .................. 1
RELEASE BEARING AND FORK ............. 6
GENERAL INFORMATION
Throughout this group, references may be made to
a particular vehicle by letter or number designation.
A chart showing the breakdown of these designations
is included in the Introduction Section at the front of
this service manual. The clutch used in all models are a single, dry disc
type with no adjustment for wear being provided in
the clutch itself. The clutch pedal is connected to the release shaft
through a cable and lever. The upper end of the clutch pedal pivots in the
pedal bracket on two nylon bushings. These bushings
do not require periodic lubrication.
CLUTCH CHATTER COMPLAINTS
For all clutch chatter complaints, do the following:
(1) Check for loose, misaligned, or broken engine
and transmission mounts. If present, they should be
corrected at this time. Test vehicle for chatter. If
chatter is gone, there is no need to go any further. If
chatter persists: (2) Check to see if clutch cable routing is correct
and operates smoothly. (3) Check for loose connections in drive train. Cor-
rect any problems and determine if clutch chatter
complaints has been satisfied. If not, (4) Remove transaxle. See Group 21, Manual Tran-
saxle, for procedure. (5) Check to see if the release bearing is sticky or
binding. Replace bearing, if needed. (6) Check linkage for excessive wear on bushings.
Replace all worn parts. A small amount of bearing
grease between the release shaft bushings and the
shaft is beneficial, but not required. (7) Check flywheel and clutch pressure plate for
contamination (dirt, oil) or scored. Replace flywheel
and/or pressure plate, if required. (8) Check to see if the clutch disc hub splines are
damaged. Replace with new disc. (9) Check input shaft splines for damage. Replace
if necessary. (10) Check for uneven wear on clutch fingers.
EXCESSIVE CLUTCH SPIN TIME/CLASH INTO
REVERSE COMPLAINTS
For all excessive clutch spin time/clash into reverse
complaints, do the following: (1) Depress clutch pedal to floor and hold. After
three seconds, shift to reverse. If clash is present,
clutch has excessive spin time. (2) Remove transaxle. See Group 21, Manual Tran-
saxle, for procedure. (3) Check the input shaft spline, clutch disc splines
and release bearing for dry rust. If present, clean
rust off and apply a light coat of bearing grease to
the input shaft splines. Apply grease on the input
shaft splines only where the clutch disc slides. (4) Check to see if the clutch disc hub splines are
damaged, replace with new disc if required. (5) Check the input shaft for damaged splines. Re-
place as necessary. (6) Check for excessive clutch disc runout or
warpage. (7) Install clutch assembly and transaxle.
CLUTCH CABLE MECHANISM
The manual transaxle clutch release system has a
unique self-adjusting mechanism to compensate for
clutch disc wear. This adjuster mechanism is located
within the clutch pedal. The preload spring main-
tains tension on the cable. This tension keeps the
clutch release bearing continuously loaded against
the fingers of the clutch cover assembly. When the pedal is depressed, teeth on the adjuster
and the positioner engage and pull the release cable.
A spring located behind the adjuster ensures proper
tooth engagement. When the pedal is released, the adjuster contacts
the bumper. This separates the adjuster and posi-
tioner teeth, allowing the preload spring to function.
Ä MANUAL TRANSAXLE CLUTCH 6 - 1

(3) Clean the flywheel face with medium sandpa-
per (80-160 grade), then wipe the surface with min-
eral spirits. If the surface is severely scored, heat
checked, or warped, replace the flywheel.
CAUTION: Do not flat-machine the flywheel face.
The surface profile is tapered.
(4) The heavy side of the flywheel is indicated by a
daub of white paint near the outside diameter. To
minimize the effects of flywheel unbalance, perform
the following installation procedure: (a) Loose assemble the flywheel to the crank-
shaft. Use new flywheel attaching bolts which have
sealant on the threads. If new bolts are not avail-
able, apply Loctite sealant to the threads of the
original bolts. This sealant is required to prevent
engine oil leakage. (b) Rotate the flywheel and crankshaft until the
daub of white paint (heavy side) is at the 12 o'clock
position. (c) Torque flywheel attaching bolts to 95 N Im(70
ft. lbs.). Use a crisscross pattern when tightening
bolts.
(5) The disc assembly should be handled without
touching the facings. Replace disc if the facings show
evidence of grease or oil soakage, or wear to within
less than .38 mm (.015 inch) of the rivet heads. The
splines on the disc hub and transaxle input shaft
should be a snug fit without signs of excessive wear.
Metallic portions of disc assembly should be dry and
clean, and not been discolored from excessive heat.
Each of the arched springs between the facings
should not be broken and all rivets should be tight. (6) Wipe the friction surface of the pressure plate
with mineral spirits. (7) Using a straight edge, check clutch cover (pres-
sure plate) for flatness. The clutch cover (pressure
plate) friction area should be slightly concave, with
the inner diameter 0.02 mm to 0.1 mm (.0008 in. to
.0039 in.) below the outer diameter. It should also be
free from discoloration, burned areas, cracks,
grooves, or ridges. (8) Using a surface plate, test cover for flatness.
All sections around attaching bolt holes should be in
contact with surface plate within .015 inch. (9) The cover should be a snug fit on flywheel dow-
els. If the clutch assembly does not meet these re-
quirements, it should be replaced.
INSTALLATION
(1) Mount clutch assembly on flywheel,being care-
ful to properly align dowels and the alignment marks
made before removal. The flywheel side of the clutch
disc is marked for proper installation. If new clutch
or flywheel is installed, align cover balance spot as
close as possible to flywheel balance orange spot. Ap-
ply pressure to the alignment tool. Center the tip of the tool into the crankshaft and the sliding cone into
the clutch fingers. Tighten the clutch attaching bolts
sufficiently to hold the disc in position. (2) To avoid distortion of the clutch cover, bolts
should be tightened a few turns at a time, in a criss-
cross pattern, until they are all seated. Tighten bolts
to 28 N Im (250 in. lbs.) following a crisscross pattern
sequence. Remove clutch disc alignment tool. (3) Install transaxle. See group 21, Manual Tran-
saxle, for procedures.
RELEASE BEARING AND FORK
Remove the transaxle from the vehicle. See group
21 for removal and installation procedures.
REMOVAL AND INSTALLATION
(1) Remove clutch release shaft E-clip.
(2) Remove the clutch release shaft and then slide
the fork and bearing assembly off the bearing pilot. (3) Remove the fork from the bearing thrust plate.
(4) Examine the condition of the bearing. It is pre-
lubricated and sealed and should not be im-
mersed in oil or solvent. (5) The bearing should turn smoothly when held in
the hand under a light thrust load. A light drag
caused by the lubricant fill is normal. If the bearing
is noisy, rough, or dry, replace the complete bearing
assembly with a new bearing. (6) The bearing has a plastic sleeve pre-lubricated
at assembly. Wipe out the old grease. Refill the
sleeve cavities and coat the inner surface with mul-
tipurpose grease. If the liner is cracked or worn, re-
place the bearing assembly. (7) Check the condition of the spring clips. If the
clips are broken or distorted, replace the bearing as-
sembly. (8) Before assembling the fork, lubricate the
rounded thrust pads and the spring clip cavities with
multipurpose grease. (9) Assemble the fork to the bearing by sliding the
thrust pads under the spring clips. Be careful to
avoid distorting the spring clips. These clips prevent
the bearing thrust plate from rotating with the bear-
ing. (10) Slide the bearing and fork assembly onto the
input shaft bearing retainer. (11) Position the release shaft bushings in the
housing and install the release shaft. A small
amount of bearing grease between the release shaft
bushing and the shaft is beneficial but not required.
Install the retainer clip in the shaft groove near the
large bushing. (12) Install the release lever and retaining clip on
the outer end of the release shaft.
CLEANING PRECAUTIONS
Condensation from steam vapors tend to accumu-
late on the internal clutch mechanism when the ve-
6 - 6 MANUAL TRANSAXLE CLUTCH Ä

(5) Install drive belt. See Accessory Drive Belts
this group. (6) Install right front lower fender shield.
(7) Refill Cooling System. See Refilling Cooling
System in this section.
ENGINE THERMOSTATS
The 2.2 and 2.5L engine thermostats are located on
the front of the engine (radiator side) in the water
box which is part of the cylinder head construction
(Fig. 9). Turbo III thermostat is located in the water
box located on the driver side of the cylinder head
(Fig. 10). These thermostats do not have an air bleed notch.
The 3.0L engine thermostat is located in a water
box, formed in the timing belt end of the intake man-
ifold. This thermostat has an air bleed valve, located
in the thermostat flange (Fig. 11). The 3.3/3.8L engine thermostat is located in a wa-
ter box, formed in the drive belt side of the intake
manifold (Fig. 13).
DESCRIPTION AND OPERATION
The engine cooling thermostats are wax pellet
driven, reverse poppet choke type. They are designed
to provide the fastest warm up possible by prevent-
ing leakage through them and to guarantee a mini-
mum engine operating temperature of 88 to 93ÉC
(192 to 199ÉF). They also automatically reach wide
open so they do not restrict flow to the radiator as
temperature of the coolant rises in hot weather to
around 104ÉC (220ÉF). Above this temperature the
coolant temperature is controlled by the radiator,
fan, and ambient temperature, not the thermostat.
OPERATION AND TESTING
The thermostat is operated by a wax filled con-
tainer (pellet) which is sealed so that when heated to
a predetermined temperature. The wax expands
enough to overcome the closing spring and water
pump pressure, which forces the valve to open. Cool-
ant leakage into the pellet will cause a thermostat to
fail open. Do not attempt to free up a thermostat
with a screwdriver. The open too soon type failure mode is included in
the onboard diagnosis. The check engine light will
not be lit by an open too soon condition. If it has
failed open, code 17 will be set. Do not change a ther-
mostat for lack of heat by gauge or heater perfor-
mance, unless code 17 is present, see diagnosis for
other probable causes. Failing shut is the normal
long term mode of failure, and normally, only on
high mileage vehicles. The temperature gauge will
indicate this, Refer to diagnosis in this section.
REMOVAL
(1) Drain cooling system down to thermostat level
or below. (2) Remove thermostat housing bolts and housing
(Figs. 9, 10, 11 and 13). (3) Remove thermostat, discard gasket and clean
both gasket sealing surfaces.
INSTALLATIONÐ2.2/2.5L AND TURBO III ENGINES
Place a new gasket (dipped in clean water) on wa-
ter box surface, center thermostat in water box on
gasket. Place housing over gasket and thermostat,
making sure thermostat is in the thermostat hous-
ing. Bolt housing to water box (Figs. 9 and 10).
Tighten bolts to 28 N Im (250 in. lbs.). Refill cooling
system (see Refilling System ).
INSTALLATIONÐ3.0L ENGINE
Center thermostat in water box pocket. Check that
the flange is seated correctly in the countersunk por-
tion of the intake manifold water box (Figs. 11 and
12). Install new gasket on water box. Install housing
over gasket and thermostat and tighten bolts to 12
N Im (133 in. lbs. torque).
Fig. 9 Thermostat, Housing, and Water BoxÐ2.2/
2.5L Engine
Fig. 10 Thermostat, Housing, and Water BoxÐTurbo III
Ä COOLING SYSTEM 7 - 13

-37ÉC (-35ÉF) to -59ÉC (-50ÉF). If it looses color or
becomes contaminated, drain, flush, and replace with
fresh properly mixed solution.
SERVICE
Coolant should be changed at 52,500 miles or three
years, whichever occurs first, then every two years or
30,000 miles.
ROUTINE LEVEL CHECK
Do not remove radiator cap for routine coolant
level inspections. The coolant reserve system provides a quick visual
method for determining the coolant level without re-
moving the radiator cap. Simply observe, with the
engine idling and warmed up to normal operating
temperature, that the level of the coolant in the reserve
tank (Figs. 5 and 6) is between the minimum and
maximum marks.
ADDING ADDITIONAL COOLANT
The radiator cap should not be removed. When
additional coolant is needed to maintain this level, it
should be added to the coolant reserve tank. Use only
50/50 concentration of ethylene glycol type antifreeze
and water.
SERVICE COOLANT LEVEL
The cooling system is closed and designed to main-
tain coolant level to the top of the radiator. When servicing requires a coolant level check in the
radiator, the engine must be offand notunder pres-
sure. Drain several ounces of coolant from the radiator
drain cock while observing the Coolant Recovery Sys-
tem (CRS) Tank. Coolant level in the CRS tank should
drop slightly. Then remove the radiator cap. The radia-
tor should be full to the top. If not, and the coolant level
in the CRS tank is at the MIN mark there is a air leak
in the CRS system. Check hose or hose connections to
the CRS tank, radiator filler neck or the pressure cap
seal to the radiator filler neck for leaks.
LOW COOLANT LEVEL AERATION
Low coolant level in a cross flow radiator will equal-
ize in both tanks with engine off. With engine at
running operating temperature the high pressure inlet
tank runs full and the low pressure outlet tank drops.
If this level drops below the top of the transmission oil
cooler, air will be sucked into the water pump:
² Transmission oil will become hotter.
² High reading shown on the temperature gauge.
² Air in the coolant will also cause loss of flow through
the heater.
² Exhaust gas leaks into the coolant can also cause the
same problems.
DEAERATION
Air can only be removed from the system by gather-
ing under the pressure cap. On the next heat up it will
be pushed past the pressure cap into the CRS tank by
thermal expansion of the coolant. It then escapes to the
atmosphere in the CRS tank and is replaced with solid
coolant on cool down.
COOLING SYSTEM DRAIN, CLEAN, FLUSH AND
REFILL
Drain, flush, and fill the cooling system at the
mileage or time intervals specified in the Maintenance
Schedule in this Group. If the solution is dirty or rusty
or contains a considerable amount of sediment, clean
and flush with a reliable cooling system cleaner. Care
should be taken in disposing of the used engine coolant
from your vehicle. Check governmental regulations for
disposal of used engine coolant.
DRAINING
To drain cooling system move temperature selector
for heater to full heat with engine running (to provide
vacuum for actuation). Without removing radiator
pressure cap and with system not under pres-
sure, Shut engine off and open draincock. The coolant
reserve tank (Fig. 5) should empty first, then remove
radiator pressure cap. (if not, see Testing Cooling
System for leaks). To vent 2.2/2.5L engines remove the
plug above thermostat housing (Fig. 1). For Turbo III
engines remove coolant temperature sensor in the
thermostat housing (Fig. 2). For 3.3L /3.8L engine
remove the engine temperature sending unit (Fig. 3).
Removal of a plug or other component is required
because the thermostat has no air vent and prevents
air flow through it. This allows the coolant to drain
from the engine block.
Fig. 1 Thermostat Housing Drain/Fill PlugÐ2.2/2.5L Engines
Ä COOLING SYSTEM 7 - 15

RADIATOR PRESSURE CAP
Radiators are equipped with a pressure cap which
releases pressure at some point within a range of
97-124 kPa (14-18 psi) (Fig. 7). The system will operate at higher than atmospheric
pressure which raises the coolant boiling point allow-
ing increased radiator cooling capacity. There is also a vent valve in the center of the cap that
allows a small coolant flow to the CRS tank. If valve is
stuck shut, the radiator hoses will be collapsed
on cool down. Clean the vent valve (Fig. 7) to
ensure proper sealing when boiling point is
reached.
There is also a gasket in the cap to seal to the top of
the filler neck so that vacuum can be maintained for
drawing coolant back into the radiator from the coolant
reserve system tank.
RADIATOR CAP TO FILLER NECK SEAL PRES- SURE RELIEF CHECK
The pressure cap upper gasket (seal) pressure relief
can be checked by removing the overflow hose at the
radiator filler neck nipple (Fig. 7). Attach the Radiator
Pressure Tool to the filler neck nipple and pump air
into the radiator. Pressure cap upper gasket should
relieve at 69-124 kPa (10-18 psi) and hold pressure at
55 kPa (8 psi) minimum.
WARNING: THE WARNING WORDS DO NOT OPEN
HOT ON THE RADIATOR PRESSURE CAP IS A
SAFETY PRECAUTION. WHEN HOT, PRESSURE
BUILDS UP IN COOLING SYSTEM. TO PREVENT
SCALDING OR INJURY, THE RADIATOR CAP
SHOULD NOT BE REMOVED WHILE THE SYSTEM IS
HOT AND/OR UNDER PRESSURE.
There is no need to remove the radiator cap at any
time except for the following purposes:
(1) Check and adjust antifreeze freeze point.
(2) Refill system with new antifreeze.
(3) Conducting service procedures.
(4) Checking for vacuum leaks.
WARNING: IF VEHICLE HAS BEEN RUN RECENTLY,
WAIT 15 MINUTES BEFORE REMOVING CAP. THEN PLACE A SHOP TOWEL OVER THE CAP AND WITH-
OUT PUSHING DOWN ROTATE IT COUNTER-
CLOCKWISE TO THE FIRST STOP. ALLOW FLUIDS
TO ESCAPE THROUGH THE OVERFLOW TUBE AND
WHEN THE SYSTEM STOPS PUSHING COOLANT
AND STEAM INTO THE CRS TANK AND PRESSURE
DROPS PUSH DOWN AND REMOVE THE CAP COM-
PLETELY. SQUEEZING THE RADIATOR INLET HOSE
WITH A SHOP TOWEL (TO CHECK PRESSURE) BE-
FORE AND AFTER TURNING TO THE FIRST STOP IS
RECOMMENDED.
PRESSURE TESTING RADIATOR CAPS
Dip the pressure cap in water, clean any deposits off
the vent valve or its seat and apply cap to end of
Radiator Pressure Tool. Working the plunger, bring the
pressure to 104 kPa (15 psi) on the gauge. If the
pressure cap fails to hold pressure of at least 97 kPa
(14 psi) replace cap. See CAUTION
If the pressure cap tests properly while positioned on
Radiator Pressure Tool, but will not hold pressure or
vacuum when positioned on the radiator. Inspect the
radiator filler neck and cap top gasket for irregularities
that may prevent the cap from sealing properly.
CAUTION: Radiator Pressure Tool is very sensitive to
small air leaks which will not cause cooling system
problems. A pressure cap that does not have a
history of coolant loss should not be replaced just
because it leaks slowly when tested with this tool.
Add water to the tool. Turn tool upside down and
recheck pressure cap to confirm that cap is bad.
INSPECTION
Hold the cap in hand, right side up(Fig. 7). The
vent valve at the bottom of the cap should open. If the
rubber gasket has swollen and prevents the valve from
opening, replace the cap. Hold the cleaned cap in hand upside down.If any
light can be seen between vent valve and rubber
gasket, replace cap. Do not use a replacement cap
that has a spring to hold the vent shut. Replacement cap must be of the type designed for
coolant reserve systems. This design assures coolant
return to radiator.
RADIATORS
The radiators are crossflow types (horizontal tubes)
with design features that provide greater strength as
well as sufficient heat transfer capabilities to keep the
engine satisfactorily cooled.
CAUTION: Plastic tanks, while stronger then brass
are subject to damage by impact, such as wrenches.
Fig. 7 Radiator Pressure Cap Filler Neck
7 - 18 COOLING SYSTEM Ä

ENGINE BLOCK HEATER
DESCRIPTION AND OPERATION
On all models an engine block heater is available as
an optional accessory. The heater, operated by ordinary
house current (110 Volt A.C.) through a power cord and
connector behind the radiator grille, provides easier
engine starting and faster warm-up when vehicle is
operated in areas having extremely low temperatures.
The heater is mounted in a core hole (in place of a core
hole plug) in the engine block, with the heating ele-
ment immersed in coolant (Fig. 9). The power cord must be secured in its retainer
clips, and not positioned so it could contact link-
ages or exhaust manifolds and become damaged. If unit does not operate, trouble can be in either the
power cord or the heater element. Test power cord for
continuity with a 110-volt voltmeter or 110-volt test
light; test heater element continuity with an ohmmeter
or 12-volt test light.
REMOVAL
(1) Drain coolant from radiator and cylinder block.
Refer to Cooling System Drain, Clean, Flush and Re-
fill of this section for procedure. (2) Detach power cord plug from heater.
(3) Loosen screw in center of heater. Remove
heater assembly.
INSTALLATION
(1) Thoroughly clean core hole and heater seat.
(2) Insert heater assembly with element loop posi-
tioned upward.
(3) With heater seated, tighten center screw se-
curely to assure a positive seal. (4) Fill cooling system with coolant to the proper
level, vent air, and inspect for leaks. Pressurize sys-
tem with Radiator Pressure Tool before looking for
leaks.
Fig. 9 Engine Block Heater
7 - 28 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

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

After 15 seconds, record the loaded voltage reading
and return the load control to the off position. (6) Voltage drop will vary according to battery
temperature at the time of the load test. Battery
temperature can be estimated by the temperature of
exposure over the preceding several hours. If the bat-
tery has been charged, boosted, or loaded a few min-
utes prior to the test, the battery would be slightly
warmer. Refer to Fig. 14 for proper loaded voltage
reading.
(7) If battery passes load test, it is in good condi-
tion and further tests are not necessary. If it fails
load test, it should be replaced.
BATTERY CHARGING
A battery is considered fully charged when it will
meet all the following requirements:
² It has an open circuit voltage charge of at least
12.4 volts (Fig. 9)
² It passes the 15 second load test (Fig. 14)
² The built in test indicator dot is GREEN (Fig. 5)
² The battery cannot be refilled with water. It must
be replaced WARNING: DO NOT CHARGE A BATTERY THAT
HAS EXCESSIVELY LOW ELECTROLYTE LEVEL.
BATTERY MAY SPARK INTERNALLY AND EX-
PLODE. EXPLOSIVE GASES FORM OVER THE BATTERY.
DO NOT SMOKE, USE FLAME, OR CREATE
SPARKS NEAR BATTERY. DO NOT ASSIST BOOST OR CHARGE A FROZEN
BATTERY. BATTERY CASING MAY FRACTURE. BATTERY ACID IS POISON, AND MAY CAUSE SE-
VERE BURNS AND THE BATTERY CONTAIN SUL-
FURIC ACID. AVOID CONTACT WITH SKIN, EYES,
OR CLOTHING. IN THE EVENT OF CONTACT,
FLUSH WITH WATER AND CALL PHYSICIAN IMME-
DIATELY. KEEP OUT OF REACH OF CHILDREN.
CAUTION: Disconnect the battery negative cable
first (Fig. 15) before charging battery to avoid dam-
age to electrical systems. Do not exceed 16.0 volts
while charging battery. Refer to the instructions
supplied with charging equipment
Battery electrolyte will bubble inside the battery
case while being charged properly. If the electrolyte
boils violently, or is discharged from the vent holes
while charging, immediately reduce charging rate or
turn off charger. Evaluate battery condition. Battery
damage may occur if charging is excessive. Some battery chargers are equipped with polarity
sensing devices to protect the charger or battery from
being damaged if improperly connected. If the bat-
tery state of charge is too low for the polarity sensor
to detect, the sensor must be bypassed for charger to
operate. Refer to operating instructions provided
with battery charger being used.
CAUTION: Charge battery until test indicator ap-
pears green. Do not overcharge.
It may be necessary to jiggle the battery or vehicle
to bring the green dot (in the test indicator) into
view. After the battery has been charged to 12.4 volts or
greater, perform a load test to decide cranking capac-
Fig. 13 Load 50 Percent Cold Crank Rating
Fig. 14 Load Test Temperature
Fig. 15 Disconnect Negative Battery Cable
Ä BATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICS 8A - 7