1988 PONTIAC FIERO Service Repair Manual

STARTER AND CHARGING SYSTEM
SYMPTOM TABLE
noid does not click
B: Starter Solenoid clicks, but engine does
A: ENGINE DOES MOT CRANK AND
STARTER SOLENOID DOES NOT
Measure: VOLTAGE
At: STARTER
SOLENOID
Conditions:
Ignition Switch: START
Gear Selector: PARK (Automatic
Transmission) Clutch: DEPRESSED
(Manual
Transmission)
Measure
Between
Correct I For Diagnosis I
I (PPL' & I Battery I See 1 I Ground
S (PPL)
& I I
Starter Motor
mounting I Battery I See 2
bolts
If
all the voltages are correct, replace the
Starter Solenoid. Refer to Section
6D for
replacement procedures.
1. Go to Table 2 (Automatic Transmission)
or Table
3 (Manual Tranmission).
2. Clean the Starter Motor mounting bolts
and Starter Motor. Scrape off any excess
paint, rust or dirt.
COMPONENT LOCATION
....... $223. .......................... IIP harness, above Fuse Bbck.
S224. .......................... IIP harness, near LIP shroud Page-Figure
........ 201- 9-A
A: ENGINE DOES MOT CRANK AND
STARTER SOLENOID DOES NOT
CLICK (TABLE 2-AUTOMATlC
TRANSMISSION)
A: ENGINE DOES MOT CRANK AND
STARTER SOLENOID DOES MOT
CLICK (TABLE 3-MANUAL
TRAMSMiSS16N)
Measure:
VOLTAGE
At: GEAR SELECTOR SWITCH CONNECTOR
(Disconnected)
Condition:
Correct 1 For Diagnosis I
If voltage is correct, go to Table 4.
1. Go to Table 6.
(YEL) &
Ground
At: CLUTCH START SWITCH CONNECTOR
(Disconnected)
Battery See 1

STARTER AND CHARGING SYSTEM
A: ENGINE DOES NOT CRANK AND
STARTER SOLENOID DOES NOT
CLICK (TABLE 4-AUTOMATIC
TRANSMISSION)
Connect: FUSED JUMPER
At: GEAR SELECTOR SWITCH CONNECTOR
(Disconnected)
Condition:
0 Ignition Switch: START
I
Jumper I Corren Resuk I For Diagnosis I Between
I (:::LI& IEngine cranks I See 1 1
If engine cranks, replace Gear Selector
Switch. Check Gear Selector Switch
adjustment before replacing with new
switch.
1. ChecWrepair PPL (6) wire for an open.
A: ENGINE DOES NOT CRANK AND
STARTER SOLENOlD DOES NOT
CLICK (TABLE 5-MANUAL
TRANSMISSION)
Connect: FUSED JUMPER
At: CLUTCH SWITCH CONNECTOR
(Disconnected)
Condition:
I 0 lanition Switch: START I
I :if,",":: 1 Engine cranks I See 1 I
Jumper
Between
If the engine cranks, checklreplace the
Clutch Start Switch.
1. Checklrepair PPL (6) wire for an open.
A: ENGINE DOES NOT CRANK AND B:
STARTER SOLENOID CLICKS BUT
STARTER
SOLENOID DOES NOT ENGINE DOES NOT CRANK OR
CLICK (TABLE 61 CRANKS SLOWLY (TABLE 1)
Correct Result Measure:
VOLTAGE
At: IGNITION SWITCH CONNECTORS
C1 &
C2 (Connected)
For Diagnosis
I Measure ( Correct Result I For Diagnosis 1 Between
I B2 (RED)& I Battery ( See 1 I Ground
I B3 IRED'& I Battery ( See 1 1 Ground
0 Turn the Ignition Switch to START
Measure: VOLTAGE
At: BPirTERV TERMINALS
Conditions: Battery fully charged
0 Fuses lNJ1 and FPIINJ 2: REMOVED
Ignition Switch: START
Engine being cranked
See 2 IYEL' &
Ground
For Diagnosis
See
Measure
Between
Positive &
Negative Battery
Terminals
If
all the voltages are correct, checklrepair
YEL (5) wire for an open (see schematic).
1. Check RED (2) wire and Fusible Link B
(see schematic).
2. Replace Ignition Switch.
Battery
0 If
the voltage is correct, go to Table 2.
1. Refer to Section 6D for Battery Load
Test. Remove Starter Assembly for
repairs if the Battery is
OK.
Correct
Voltage
Greater than
9.5 volts

STARTER AND CHARGING SYSTEM
: STARTER SOLENOID CLICKS BUT
ENGINE DOES NOT CRANK OR
CRANKS SLOWLY (TABLE
2)
Battery fully charged
Fuses
lNJl and FPIINJ 2: REMOVED
Starter Assembly for repairs. Refer to
1. Replace negative battery cable.
2. Replace positive battery cable.
CIRCUIT OPERATION
STARTER
Wen the Ignition Switch is moved to the
START position with the Gear Selector Switch
in PARK or NEUTRAL (automatic
transrnis-
sion) or the Clutch Start Switch closed (manual
transmission), battery voltage is applied to the
Starter Solenoid. Both solenoid windings are
energized. The circuit through the Pull-In
Winding is completed to ground through the
Starter Motor. The windings work together
magnetically to pull in and hold in the Plunger.
The Plunger moves the Shift Lever. This action
causes the Drive Assembly to rotate as
it
engages the Flywheel Gear on the engine. At
the same time, the Plunger also closes the Sole-
noid Switch contacts in the Starter Solenoid.
Full battery voltage is applied directly to the
Starter Motor and it cranks the engine.
As soon as the Solenoid Switch contacts
close, current no longer flows through the Pull-
In Winding since battery voltage is applied to
both ends of the winding. The Nold-In Winding
remains energized and its magnetic field is
strong enough to hold the Plunger, Shift Lever,
Drive Assembly, and Solenoid Switch contacts
in place to continue cranking the engine.
When the Ignition Switch is released from
the START position, battery voltage is
removed from the PPL wire and the junction of
the two windings. Current flows from the motor
contacts, through both windings, to ground at
the end of the Hold-In Winding. However, the
direction of current flow through the Pull-In
Winding is now opposite to the direction of
current flow when the winding was first ener
gized. The magnetic fields of the Pull-In and
Hold-In Windings now oppose one another.
This action of the windings, with the help of the
Return Spring, causes the starter Drive Assem-
bly to disengage and Solenoid Switch contacts
open, the Starter Circuit is turned off.

STARTER AND CHARGING SYSTEM: V6 VIN S

a STARTER AND CHARGING SYSTEM: V8 VIN F, V8 VlN 8 C

STARTER AND CHARGING SYSTEM: V8 VIN E
CHARGING WITHOUT DIGITAL CLUSTER WITH DIGITAL CLUSTER
------ I= I FUSE C/H-FAN I BLOCK I GAGES FUSE =K FUSE - SEE FUSE I
( BLOCK DETAILS I
--,,--a

STARTER AND CHARGING SYSTEM
TROUBLESHOOTING HINTS
CHARGING
* Try the following checks before doing the Sys-
tem Diagnosis
.
1 . Check the hydrometer eye that is built into
the vehicle Battery before troubleshooting
the Charging System
.
- Green eye . Battery is charged .
. Dark eye . Battery is discharged . Recharge
Battery
.
- Clear or yellow eye . Battery fluid is low .
Replace Battery .
2 . Check the Generator Belt .
3 . Check that the Starter Solenoid terminal B
and battery connections are clean and tight
.
4 . Check that the Generator connector is tight
and that the Generator battery terminal is
clean and tight
.
5 . Check the vehicle voltmeter (if equipped) to
assure accurate voltage readings
.
6 . Check the GAGES Fuse . This check can be
done by observing the BRAKE Warning
Indicator with the Ignition Switch in RUN
and the Park Brake applied
.
7 . Check the GIN-FAN Fuse .
Go to System Diagnosis for diagnostic tests .
COMPONENT LOCATION Page-Figure
Coolant Fan Relay (VIN
E) ......... LH rear corner of engine compartment. on relay
bracket
................................. 201- 3-A
Coolant Fan Relay (VIN F) (VIN 8)
. . Front of engine compartment. RH side of
radiator support
.......................... 201- 5-A
Coolant Fan Relay (VIN S)
......... LN rear corner of engine compartment. on relay
bracket
................................. 201- 0-A
Fuel Pump In-Line Fuse
........... RH side of engine compartment. on inner fender
panel
................................... 201- 1-A
Fuse Block
...................... Behind LN side of IIP. below light switch ....... 201-10-A
Fusible Link H (VIN E)
........... RH front of engine compartment. at Junction
................................... Block 201- 3-B
Fusible Link
H (VIN S) ............ Lower RN side of engine. at Starter Solenoid .... 201- 1-A
Fusible Link
J (VIN E) ............ Lower RH side of engine. at Starter Solenoid .... 201- 2-A
Fusible Link
J (VIN F) (VIN 8) ..... Lower RH side of engine. at Starter Solenoid .... 201- 6-B
Fusible Link
J (VIN S) ............ RH side of radiator support. at Junction Block .. 201- 1-A
Fusible Link
K .................. RH front of engine compartment. at Junction
................................... Block 201- 3-B
In-Line Fuse (VIN E)
............. RH inner fender panel by battery ............. 201- 3-B
In-Line Fuse (VIN
F)(VIN 8) ....... On LH side of radiator support. forward of
................................. battery 201- 5-6
.................. Junction Block RH
front of engine compartment. behind
................................ headlight 201- 1-A
........ Mass Air Flow In-Line Fuse RR side of engine compartment. on inner fender
................................... panel 201- 1-A
Starter Solenoid (VIN E)
.......... Lower RH side of engine .................... 201- 2-A
Starter Solenoid (VIN F) (VIN
8) .... Lower RH side of engine .................... 201- 6-B
Starter Solenoid (VIN S)
.......... Lower RN side of engine .................... 201- 1-A
el00 (42 cavities) ................ LH front of dash. left of brake master cylinder .. 201- 0-A
C207 (15 cavities)
................ Behind RH side of IIP. near ECM ............. 201-13-A
G100 (VIN E) ................... RH front of engine ......................... 201- 4-B
G100 (VIN F) (VIN 8) ............. Lower LH front of engine .................... 201- 8-B
G100 (VIN S) .................... Lower LH front of engine .................... 201- 1-B
6103 (Except VIN E) ............. On radiator support. behind LH headlights ..... 201-16-A
6.103 (VIN E) ................... RH inner fender panel. near battery ........... 201- 3-B
S204
........................... IIP harness. behind instrument cluster ......... 201-10-A
S206 (VIN
E) .................... Engine harness. RH front of dash ............. 201- 2-A
(Continued on facing page)

STARTER AND CHARGING SYSTEM
SYSTEM DIAGNOSIS
CHARGING Do the tests below if the Battery is under-
charged or overcharged or if the vehicle
voltmeter shows less than
12 volts or more
than
16 volts with the engine running at fast
idle.
GENERATOR TEST (TABLE 1)
GENERATOR CONNECTOR
(Continued in next column)
COMPONENT LOCATION Page-Figure
...... S206 (VIN F)(VIN 8). ............. Engine harness, top center rear of engine.
201- 7-A
.......... S206 (VIN S) .................... Engine harness, above rear of engine
201- 1-A
(Continued from previous column)
If
all voltages are correct, reconnect the
connector and go to Table 2.
1. Check GAGES Fuse, BRN (25) wire,
PNKIBLK (39) wire and the Instrument
Cluster Printed Circuit for an open or
short to ground.
2. Check
CIH-FAN FUSE and the BRN
(250) wire for an open or short to ground
(see schematic).
3. Check RED (2) wire and Fusible Link (see
schematic) for an open or short to ground.
4. Check wiring from the battery positive
terminal of the Generator (see schematic).
GENERATOR TEST (TABLE 2)
Measure: VOLTAGE
At: GENERATOR
Conditions: Generator Connector: CONNECTED
All accessories: OFF
Engine running at fast idle
Measure I Correct Resuk I For Diagnosis / 1 Between
Battery
terminal
& Less than 16
1 Ground 1 1 See 1
If the voltage is correct, perform a Gener-
ator Load Test. Refer to Section 6D. Per-
form a Battery Load Test if the Generator
is good. Refer to Section 6D.
1. Repairlreplace Generator. Refer to Sec-
tion 6D.
CIRCUIT OPERATION
CHARGING
The Generator provides voltage to operate
the car's electrical system and to charge its
battery. A magnetic field is created when cur-
rent flows through the Rotor. This field rotates
as the Rotor is driven by the engine, creating an
AC voltage in the Stator windings. The AC
voltage is converted to DC by the rectifier
bridge and is supplied to the electrical system
at the Battery ter
The Generator's Regulator uses digital tech-
niques to supply the Rotor current and thereby
control the output voltage. The Rotor current is
proportional to the width of the electrical
pulses supplied by the Regulator. When the
Ignition Switch is placed in RUN, voltage is
supplied to terminals L and F, turning on the
Regulator. Narrow width pulses are supplied to
the Rotor, creating a weak magnetic field.
When the engine is started, the Regulator
senses Generator rotation by detecting
AC
voltage at the stator through an internal wire.
Once the engine is running, the Regulator var-
ies the field current by controlling the pulse
width. This regulates the Generator output
voltage for proper battery charging and elec-
trical system operation.