battery DODGE NEON 1999 Service Owner's Guide

CHARGING SYSTEM
CONTENTS
page page
GENERAL INFORMATION
OVERVIEW............................. 1
DESCRIPTION AND OPERATION
BATTERY TEMPERATURE SENSOR.......... 2
CHARGING SYSTEM OPERATION........... 1
ELECTRONIC VOLTAGE REGULATOR......... 2
GENERATOR............................ 2
DIAGNOSIS AND TESTING
BATTERY TEMPERATURE SENSOR.......... 8
CHARGING SYSTEM RESISTANCE TESTS..... 5CHARGING SYSTEM...................... 2
CURRENT OUTPUT TEST.................. 8
ON-BOARD DIAGNOSTIC SYSTEM TEST..... 10
REMOVAL AND INSTALLATION
BATTERY TEMPERATURE SENSOR......... 11
GENERATOR........................... 10
SPECIFICATIONS
GENERATOR RATINGS................... 12
TORQUE.............................. 12
GENERAL INFORMATION
OVERVIEW
The battery, starting, and charging systems oper-
ate with one another, and must be tested as a com-
plete system. In order for the vehicle to start and
charge properly, all of the components involved in
these systems must perform within specifications.
Group 8A covers the battery, Group 8B covers the
starting system, and Group 8C covers the charging
system. Refer to Group 8W - Wiring Diagrams for
complete circuit descriptions and diagrams. We have
separated these systems to make it easier to locate
the information you are seeking within this Service
Manual. However, when attempting to diagnose any
of these systems, it is important that you keep their
interdependency in mind.
The diagnostic procedures used in these groups
include the most basic conventional diagnostic meth-
ods to the more sophisticated On-Board Diagnostics
(OBD) built into the Powertrain Control Module
(PCM). Use of an induction ammeter, volt/ohmmeter,
battery charger, carbon pile rheostat (load tester),
and 12-volt test lamp may be required.
All OBD-sensed systems are monitored by the
PCM. Each monitored circuit is assigned a Diagnos-
tic Trouble Code (DTC). The PCM will store a DTC in
electronic memory for any failure it detects. See the
On-Board Diagnostics Test in Group 8C - Charging
System for more information.
DESCRIPTION AND OPERATION
CHARGING SYSTEM OPERATION
The charging system consists of:
²Generator
²Electronic Voltage Regulator (EVR) circuitry
within the Powertrain Control Module (PCM)
²Ignition switch (refer to Group 8D, Ignition Sys-
tem for information)
²Battery (refer to Group 8A, Battery for informa-
tion)
²Battery temperature sensor
²Voltmeter (refer to Group 8E, Instrument Panel
and Gauges for information)
²Wiring harness and connections (refer to Group
8W, Wiring for information)
The charging system is turned on and off with the
ignition switch. When the ignition switch is turned to
the ON position, battery voltage is applied to the
generator rotor through one of the two field termi-
nals to produce a magnetic field. The generator is
driven by the engine through a serpentine belt and
pulley arrangement.
The amount of DC current produced by the gener-
ator is controlled by the EVR (field control) circuitry,
contained within the PCM. This circuitry is con-
nected in series with the second rotor field terminal
and ground.
PLCHARGING SYSTEM 8C - 1

A battery temperature sensor located on the front
bumper beam is used to sense battery temperature.
This temperature data, along with data from moni-
tored line voltage, is used by the PCM to vary the
battery charging rate. This is done by cycling the
ground path to control the strength of the rotor mag-
netic field. The PCM then compensates and regulates
generator current output accordingly and to maintain
the proper voltage depending on battery tempera-
ture.
All vehicles are equipped with On-Board Diagnos-
tics (OBD). All OBD-sensed systems, including the
EVR (field control) circuitry, are monitored by the
PCM. Each monitored circuit is assigned a Diagnos-
tic Trouble Code (DTC). The PCM will store a DTC in
electronic memory for any failure it detects. See On-
Board Diagnostic System Test in this group for more
information.
GENERATOR
The generator is belt-driven by the engine. It is
serviced only as a complete assembly. If the genera-
tor fails for any reason, the entire assembly must be
replaced.
As the energized rotor begins to rotate within the
generator, the spinning magnetic field induces a cur-
rent into the windings of the stator coil. Once the
generator begins producing sufficient current, it also
provides the current needed to energize the rotor.
The Y type stator winding connections deliver the
induced AC current to 3 positive and 3 negative
diodes for rectification. From the diodes, rectified DC
current is delivered to the vehicle electrical system
through the generator, battery, and ground terminals.
Noise emitting from the generator may be caused
by:
²Worn, loose or defective bearings
²Loose or defective drive pulley
²Incorrect, worn, damaged or misadjusted drive
belt
²Loose mounting bolts
²Misaligned drive pulley
²Defective stator or diode
BATTERY TEMPERATURE SENSOR
The battery temperature sensor is used to deter-
mine the battery temperature. This temperature
data, along with data from monitored line voltage, is
used by the PCM to vary the battery charging rate.
System voltage will be higher at colder temperatures
and is gradually reduced at warmer temperatures.
The sensor is located on the bottom of the battery
tray (Fig. 1).
ELECTRONIC VOLTAGE REGULATOR
The Electronic Voltage Regulator (EVR) is not a
separate component. It is actually a voltage regulat-
ing circuit located within the Powertrain Control
Module (PCM). The EVR is not serviced separately. If
replacement is necessary, the PCM must be replaced.
Operation:The amount of DC current produced
by the generator is controlled by EVR circuitry con-
tained within the PCM. This circuitry is connected in
series with the generators second rotor field terminal
and its ground.
Voltage is regulated by cycling the ground path to
control the strength of the rotor magnetic field. The
EVR circuitry monitors system line voltage and bat-
tery temperature (refer to Battery Temperature Sen-
sor for more information). It then compensates and
regulates generator current output accordingly. Also
refer to Charging System Operation for additional
information.
DIAGNOSIS AND TESTING
CHARGING SYSTEM
When the ignition switch is turned to the ON posi-
tion, battery potential will register on the voltmeter.
During engine cranking a lower voltage will appear
on the meter. With the engine running, a voltage
reading higher than the first reading (ignition in ON)
should register.
The following are possible symptoms of a charging
system fault:
²The voltmeter does not operate properly
²An undercharged or overcharged battery condi-
tion occurs.
Fig. 1 Battery Temperature Sensor
8C - 2 CHARGING SYSTEMPL
DESCRIPTION AND OPERATION (Continued)

Remember that an undercharged battery is often
caused by:
²Accessories being left on with the engine not
running
²A faulty or improperly adjusted switch that
allows a lamp to stay on. See Ignition-Off Draw Test
in Group 8A, Battery for more information.
The following procedures may be used to correct a
problem diagnosed as a charging system fault.
INSPECTION
(1) Inspect condition of battery cable terminals,
battery posts, connections at engine block, starter
solenoid and relay. They should be clean and tight.
Repair as required.
(2) Inspect all fuses in the fuseblock module and
Power Distribution Center (PDC) for tightness in
receptacles. They should be properly installed and
tight. Repair or replace as required.(3) Inspect the electrolyte level in the battery.
Replace battery if electrolyte level is low.
(4) Inspect generator mounting bolts for tightness.
Replace or tighten bolts if required. Refer to the Gen-
erator Removal/Installation section of this group for
torque specifications.
(5) Inspect generator drive belt condition and ten-
sion. Tighten or replace belt as required. Refer to
Belt Tension Specifications in Group 7, Cooling Sys-
tem.
(6) Inspect automatic belt tensioner (if equipped).
Refer to Group 7, Cooling System for information.
(7) Inspect connections at generator field, battery
output, and ground terminals. Also check ground con-
nection at engine. They should all be clean and tight.
Repair as required.
PLCHARGING SYSTEM 8C - 3
DIAGNOSIS AND TESTING (Continued)

These tests will show the amount of voltage drop
across the generator output wire from the generator
output (B+) terminal to the battery positive post.
They will also show the amount of voltage drop from
the ground (-) terminal on the generator (Fig. 2) to
the battery negative post.
A voltmeter with a 0±18 volt DC scale should be
used for these tests. By repositioning the voltmeter
test leads, the point of high resistance (voltage drop)
can easily be found.
Test points on the generator may be reached by
either removing the air cleaner housing or below by
raising the vehicle on a hoist.
PREPARATION
(1) Before starting test, make sure battery is in
good condition and is fully-charged. See Group 8A,
Battery for more information.
(2) Check condition of battery cables at battery.
Clean if necessary.
(3) Start the engine and allow it to reach normal
operating temperature.
(4) Shut engine off.
(5) Connect an engine tachometer.
(6) Fully engage the parking brake.
TEST
(1) Start engine.
(2) Place heater blower in high position.
(3) Turn on headlamps and place in high-beam
position.
(4) Turn vehicle interior lamps on.
(5) Start engine. Bring engine speed up to 2400
rpm and hold.
(6) Testing (- ground) circuitry:
(a) Touch the negative lead of voltmeter directly
to battery positivePOST(Fig. 4).
(b) Touch the positive lead of voltmeter to the
B+ output terminal stud on the generator (not the
terminal mounting nut). Voltage should be no
higher than 0.6 volts. If voltage is higher than 0.6
volts, touch test lead to terminal mounting stud
nut and then to the wiring connector. If voltage is
now below 0.6 volts, look for dirty, loose or poor
connection at this point. Refer to Group 8, Wiring
for connector location. A voltage drop test may be
Fig. 2 Generator Terminals
Fig. 3 Electrical Resistance Test
Fig. 4 Battery Voltage Test
PLCHARGING SYSTEM 8C - 7
DIAGNOSIS AND TESTING (Continued)

performed at each (- ground) connection in this cir-
cuit to locate the excessive resistance.
(7) Testing (+ positive) circuitry:
(a) Touch the positive lead of voltmeter directly
to battery negativePOST.
(b) Touch the negative lead of voltmeter to the
ground terminal stud on the generator case (not
the terminal mounting nut). Voltage should be no
higher than 0.3 volts. If voltage is higher than 0.3
volts, touch test lead to terminal mounting stud
nut and then to the wiring connector. If voltage is
now below 0.3 volts, look for dirty, loose or poor
connection at this point. A voltage drop test may be
performed at each (+ positive) connection in this
circuit to locate the excessive resistance. This test
can also be performed between the generator case
and the engine. If test voltage is higher than 0.3
volts, check for corrosion at generator mounting
points or loose generator mounting.
CURRENT OUTPUT TEST
The current output test will determine if the
charging system can deliver its minimum test cur-
rent (amperage) output. Refer to the Specifications
section at the end of this group for minimum test
current (amperage) requirements.
The first part of this test will determine the com-
bined amperage output of both the generator and the
Electronic Voltage Regulator (EVR) circuitry.
PREPARATION
(1) Determine if any Diagnostic Trouble Codes
(DTC) exist. To determine a DTC, refer to On-Board
Diagnostics in this group. For repair, refer to the
appropriate Powertrain Diagnostic Procedures man-
ual.
(2) Before starting test, make sure battery is in
good condition and is fully-charged. See Group 8A,
Battery for more information.
(3) Check condition of battery cables at battery.
Clean if necessary.
(4) Perform the Voltage Drop Test. This will
ensure clean and tight generator/battery electrical
connections.
(5) Be sure the generator drive belt is properly
tensioned. Refer to Group 7, Cooling System for
information.
(6) A volt/amp tester equipped with both a battery
load control (carbon pile rheostat) and an inductive-
type pickup clamp (ammeter probe) will be used for
this test. Refer to operating instructions supplied
with tester. When using a tester equipped with an
inductive-type clamp, removal of wiring at the gener-
ator will not be necessary.
(7) Start the engine and allow it to reach operating
temperature.
(8) Shut engine off.(9) Turn off all electrical accessories and all vehicle
lighting.
(10) Connect the volt/amp tester leads to the bat-
tery. Be sure the carbon pile rheostat control is in the
OPEN or OFF position before connecting leads. See
Load Test in Group 8A, Battery for more information.
Also refer to the operating instructions supplied with
test equipment.
(11) Connect the inductive clamp (ammeter probe).
Refer to the operating instructions supplied with test
equipment.
(12) If volt/amp tester is not equipped with an
engine tachometer, connect a separate tachometer to
the engine.
TEST
(1) Perform the previous test Preparation.
(2) Fully engage the parking brake.
(3) Start engine.
(4) Bring engine speed to 2500 rpm.
(5) With engine speed held at 2500 rpm, slowly
adjust the rheostat control (load) on the tester to
obtain the highest amperage reading. Do not allow
voltage to drop below 12 volts. Record the reading.
This load test must be performed within 15 sec-
onds to prevent damage to test equipment.On
certain brands of test equipment, this load will be
applied automatically. Refer to the operating manual
supplied with test equipment.
(6) The ammeter reading must meet the Minimum
Test Amps specifications as displayed in the Genera-
tor Ratings chart. This can be found in the Specifica-
tions section at the end of this group. A label stating
a part reference number is attached to the generator
case. On some engines this label may be located on
the bottom of the case. Compare this reference num-
ber to the Generator Ratings chart.
(7) Rotate the load control to the OFF position.
(8) Continue holding engine speed at 2500. If EVR
circuitry is OK, amperage should drop below 15±20
amps. With all electrical accessories and vehicle
lighting off, this could take several minutes of engine
operation. If amperage did not drop, refer to the
appropriate Powertrain Diagnostic Procedures man-
ual for testing.
(9) Remove volt/amp tester.
If minimum amperage could not be met, refer to
the appropriate Powertrain Diagnostic Procedures
manual for testing.
BATTERY TEMPERATURE SENSOR
To perform a complete test of this sensor and its
circuitry, refer to the appropriate Powertrain Diag-
nostic Procedures manual. To test the sensor only,
refer to the following:
(1) The sensor is located under the battery and is
attached to the battery tray (Fig. 5). A two-wire pig-
8C - 8 CHARGING SYSTEMPL
DIAGNOSIS AND TESTING (Continued)

tail harness is attached directly to the sensor. The
opposite end of this harness connects the sensor to
the engine wiring harness.
(2) Disconnect the two-wire pigtail harness from
the engine harness.
(3) Attach ohmmeter leads to the wire terminals of
the pigtail harness.
(4) At room temperature of 25É C (75±80É F), an
ohmmeter reading of 9,000 (9K) to 11,000 (11K) ohms
should be observed.
(5) If reading is above or below the specification,
replace the sensor.
(6) Refer to the Removal and Installation section
for procedures.
ON-BOARD DIAGNOSTIC SYSTEM TEST
GENERAL INFORMATION
The Powertrain Control Module (PCM) monitors
critical input and output circuits of the charging sys-
tem, making sure they are operational. A Diagnostic
Trouble Code (DTC) is assigned to each input and
output circuit monitored by the OBD system. Some
circuits are checked continuously and some are
checked only under certain conditions.
If the OBD system senses that a monitored circuit
is bad, it will put a DTC into electronic memory. The
DTC will stay in electronic memory as long as the
circuit continues to be bad. The PCM is programmed
to clear the memory after 50 engine starts if the
problem does not occur again.
DIAGNOSTIC TROUBLE CODES
Refer to Group 25, On Board Diagnostic for more
information. A DTC description can be read using the
DRB scan tool. Refer to the appropriate Powertrain
Diagnostic Procedures manual for information.
A DTC does not identify which component in a cir-
cuit is bad. Thus, a DTC should be treated as asymptom, not as the cause for the problem. In some
cases, because of the design of the diagnostic test
procedure, a DTC can be the reason for another DTC
to be set. Therefore, it is important that the test pro-
cedures be followed in sequence, to understand what
caused a DTC to be set.
ERASING DIAGNOSTIC TROUBLE CODES
The DRB Scan Tool must be used to erase a DTC.
REMOVAL AND INSTALLATION
GENERATOR
REMOVAL
(1) Disconnect battery negative cable (Fig. 6).
(2) Loosen but DO NOT remove the generator
adjustment nut.
(3) Raise vehicle with front wheels turned fully to
the right.
(4) Remove the plastic lower splash shield.
(5) Disconnect the generator field circuit wiring
connector (Fig. 9). Squeeze locking tab to release.
(6) Remove the B+ terminal nut and wire.
(7) Loosen pivot bolt, but do not remove (Fig. 8)
and (Fig. 9).
(8) Remove the generator drive belt. The generator
spill shield does not need to be removed.
(9) Remove three mounting pivot bracket bolts.
(10) Remove pivot bolt and bracket.
(11) Holding the generator in one hand, remove
adjustment nut and slide the generator off the T-bolt.
The T-bolt does not need to be removed.
(12) Lower the generator and remove through the
wheel well.
INSTALLATION
(1) For installation, reverse above procedures. The
generator field connector has a locking tab and will
snap when fully installed. Refer to group 7 Cooling
System, Belt Removal/Install Adjust. Tighten all fas-
teners to the proper torque. Refer to the Torque Spec-
Fig. 5 Battery Temperature Sensor
Fig. 6 Removal/Installation of Battery Cables
8C - 10 CHARGING SYSTEMPL
DIAGNOSIS AND TESTING (Continued)

ifications chart in Group 8A, Battery/Starter/
Charging Systems Diagnostics.
BATTERY TEMPERATURE SENSOR
REMOVAL
(1) Make sure ignition switch is in OFF position
and all accessories are OFF.
(2) Remove battery negative cable first then the
positive cable (Fig. 10).
Fig. 7 Wire Terminal Connection
Fig. 8 Generator Front View
Fig. 9 Generator Rear View
Fig. 10 Removal of Battery Cables
PLCHARGING SYSTEM 8C - 11
REMOVAL AND INSTALLATION (Continued)

(3) Remove battery thermoguard (Fig. 11).
WARNING: TO PROTECT THE HANDS FROM BAT-
TERY ACID, A SUITABLE PAIR OF HEAVY DUTY
RUBBER GLOVES, NOT THE HOUSEHOLD TYPE,
SHOULD BE WORN WHEN REMOVING OR SERVIC-
ING A BATTERY. SAFETY GLASSES ALSO SHOULD
BE WORN.
(4) Remove temperature sensor mounting nut from
battery tray (Fig. 12).
(5) Disconnect sensor wire connector (Fig. 13).
INSTALLATION
For installation reverse above procedures.
SPECIFICATIONS
GENERATOR RATINGS
TORQUE
DESCRIPTION TORQUE
Battery Terminal Nut..........9N´m(75in.lbs.)
Battery Hold Down Clamp Bolt . . .9 N´m (75 in. lbs.)
Generator Mounting Bolt.......54N´m(40ft.lbs.)
Generator Pivot Bolt...........54N´m(40ft.lbs.)
TYPE PART NUMBER RATED SAE AMPS ENGINES MINIMUM TEST AMPS
MELCO 4793190 83 AMPS 2.0L SOHC/DOHC 75 AMPS
Fig. 11 Battery Thermoguard
Fig. 12 Battery Temperature Sensor Location
Fig. 13 Battery Temperature Sensor Connector
8C - 12 CHARGING SYSTEMPL
REMOVAL AND INSTALLATION (Continued)

The major difference between the two engines is
component location which affects the ignition system
service procedures. There are various sensors that
are in different locations due to a different cylinder
head and intake manifold.
The 2.0L engines use a fixed ignition timing sys-
tem. The distributorless electronic ignition system is
referred to as the Direct Ignition System (DIS).
Basic ignition timing is not adjustable.The
Powertrain Control Module (PCM) determines spark
advance. The system's three main components are
the coil pack, crankshaft position sensor, and cam-
shaft position sensor.
POWERTRAIN CONTROL MODULE
The Powertrain Control Module (PCM) controls the
ignition system (Fig. 1). The PCM supplies battery
voltage to the ignition coil through the Auto Shut-
down (ASD) Relay. The PCM also controls the ground
circuit for the ignition coil. By switching the ground
path for the coil on and off, the PCM adjusts ignition
timing to meet changing engine operating conditions.
During the crank-start period the PCM maintains
spark advance at 9É BTDC. During engine operation
the following inputs determine the amount of spark
advance provided by the PCM.
²Intake air temperature
²Coolant temperature
²Engine RPM
²Intake manifold vacuum
²Knock sensor
The PCM also regulates the fuel injection system.
Refer to the Fuel Injection sections of Group 14.
SPARK PLUGS
The 2.0L engines uses resistor spark plugs. For
spark plug identification and specifications, Refer to
the Specifications section at the end of this group.Remove the spark plugs and examine them for
burned electrodes and fouled, cracked or broken por-
celain insulators. Keep plugs arranged in the order
in which they were removed from the engine. An iso-
lated plug displaying an abnormal condition indicates
that a problem exists in the corresponding cylinder.
Replace spark plugs at the intervals recommended in
Group 0.
Spark plugs that have low mileage may be cleaned
and reused if not otherwise defective. Refer to the
Spark Plug Condition section of this group. After
cleaning, file the center electrode flat with a small
point file or jewelers file. Adjust the gap between the
electrodes (Fig. 2) to the dimensions specified in the
chart at the end of this section.
Always tighten spark plugs to the specified torque.
Over tightening can cause distortion and damage.
Tighten spark plugs to 28 N´m (20 ft. lbs.) torque.
SPARK PLUG CABLES
Spark plug cables are sometimes referred to as sec-
ondary ignition wires. The wires transfer electrical
current from the coil pack to individual spark plugs
at each cylinder. The resistor type, nonmetallic spark
plug cables provide suppression of radio frequency
emissions from the ignition system.
Check the spark plug cable connections for good
contact at the coil and spark plugs. Terminals should
be fully seated. The nipples and spark plug covers
should be in good condition. Nipples should fit tightly
on the coil. Spark plug boot should completely cover
the spark plug hole in the cylinder head cover. Install
the boot until the terminal snaps over the spark
plug. A snap must be felt to ensure the spark plug
cable terminal engaged the spark plug.
Loose cable connections will corrode, increase resis-
tance and permit water to enter the coil towers.
These conditions can cause ignition malfunction.
Fig. 1 Powertrain Control Module
Fig. 2 Setting Spark Plug Electrode Gap
8D - 2 IGNITION SYSTEMPL
DESCRIPTION AND OPERATION (Continued)

Plastic clips in various locations protect the cables
from damage. When the cables are replaced the clips
must be used to prevent damage to the cables. The
#1 cable must be routed under the PCV hose and
clipped to the #2 cable.
ELECTRONIC IGNITION COILS
WARNING: THE DIRECT IGNITION SYSTEM GEN-
ERATES APPROXIMATELY 40,000 VOLTS. PER-
SONAL INJURY COULD RESULT FROM CONTACT
WITH THIS SYSTEM.
The coil pack consists of 2 coils molded together.
The coil pack is mounted on the valve cover (Fig. 3)
or (Fig. 4). High tension leads route to each cylinder
from the coil. The coil fires two spark plugs every
power stroke. One plug is the cylinder under com-
pression, the other cylinder fires on the exhaust
stroke. Coil number one fires cylinders 1 and 4. Coil
number two fires cylinders 2 and 3. The PCM deter-
mines which of the coils to charge and fire at the cor-
rect time.
The Auto Shutdown (ASD) relay provides battery
voltage to the ignition coil. The PCM provides a
ground contact (circuit) for energizing the coil. When
the PCM breaks the contact, the energy in the coil
primary transfers to the secondary causing the
spark. The PCM will de-energize the ASD relay if it
does not receive the crankshaft position sensor and
camshaft position sensor inputs. Refer to Auto Shut-
down (ASD) RelayÐPCM Output, in this section for
relay operation.
AUTOMATIC SHUTDOWN RELAY
The Automatic Shutdown (ASD) relay supplies bat-
tery voltage to the fuel injectors, electronic ignition
coil and the heating elements in the oxygen sensors.
A buss bar in the Power Distribution Center (PDC)
supplies voltage to the solenoid side and contact sideof the relay. The ASD relay power circuit contains a
20 amp fuse between the buss bar in the PDC and
the relay. The fuse also protects the power circuit for
the fuel pump relay and pump. The fuse is located in
the PDC. Refer to Group 8W, Wiring Diagrams for
circuit information.
The PCM controls the ASD relay by switching the
ground path for the solenoid side of the relay on and
off. The PCM turns the ground path off when the
ignition switch is in the Off position. When the igni-
tion switch is in On or Start, the PCM monitors the
crankshaft and camshaft position sensor signals to
determine engine speed and ignition timing (coil
dwell). If the PCM does not receive crankshaft and
camshaft position sensor signals when the ignition
switch is in the Run position, it will de-energize the
ASD relay.
The ASD relay is located in the PDC (Fig. 5). The
inside top of the PDC cover has label showing relay
and fuse identification.
Fig. 3 Ignition Coil PackÐSOHC
Fig. 4 Ignition Coil PackÐDOHC
Fig. 5 Power Distribution Center (PDC)
PLIGNITION SYSTEM 8D - 3
DESCRIPTION AND OPERATION (Continued)