diagram PONTIAC FIERO 1988 Service Workshop Manual

POWER DISTRIBUTION
CIRCUIT OPERATION
Electrical power for the car is provided by the
Generator when the engine is running. The
schematic diagram shows how each circuit gets
its power. For more details about the Gener-
ator, and connections to the Battery and
Starter, see Starter and Charging System, Sec-
tion
8A-30.
The car's Power Distribution System con-
sists of Fusible Links, Fuses, Circuit Breakers,
the Light Switch and the Ignition Switch. Fusi-
ble Links are short pieces of wire to which they
supply power. They are covered with a special
high-temperature insulation. When conducting
a high current, the Fusible Link will melt and
stop current flow. They are designed to protect
the car's electrical system from electrical
shorts where it is not protected by the Circuit
Breakers and Fuses. See Fuse Block Details
and Light Switch Details for complete wiring to
the first component in each circuit.
The Ignition Switch has six positions, five of
which have detents. The BULB TEST position
is after the RUN position and just before the
START position. BULB TEST does not have a
detent. As shown in the schematic, circuits
which are supplied from the Ignition Switch are
On (Hot) for different switch positions. Indi-
vidual schematics show their fuses supplied
from headings such as "Not In Run. "The head-
ing corresponds to the Ignition Switch position
in which power is On.

LIGHTING SYSTEMS AND HORNS 8B-3
HORNS the steering wheel sounds the horn by closing the horn
relay (in the convenience center behind the instrument
panel, to the right of the steering column). The horns
The holm(§) are mounted behind the front fascia use a solenoid-operated diaphragm to generate sound.
on the driver's side. $ushing the pad in the center of See Section 8A-40 for wiring and circuit information.
ON-CAR SERVICE
Wiring diagrams and other diagnosis information
is given in Section
8A. Information on properly
repairing wiring harnesses, connectors, etc., is on
8A-5.
Most lighting problems are caused by loose
connectors, open or shorted wiring, burned-out bulbs,
bad switches, inadequate ground or blown fuses. Many
of these require only replacement of a defective part.
When replacing a part that requires a special procedure
(such as a lens and housing assembly sealed together),
follow the instructions normally included in the
replacement parts package.
When removing a part that requires special
sealing items (such as sealing washers), be sure to
reinstall those items when replacing the part. Also, if
any body sealing items (grommets, etc.) are disturbed,
be sure to repair them so the passenger compartment
remains properly sealed.
EXTERlOR LIGHTS
BACK-UP LIGHTS
Fig. 8B-8
Replacement Bulb: Trade No. 1156, 32
Candlepower
To replace a back-up light bulb, see "Rear
Tail/Stop/Turn Signal Lights9' in this section. For
information on the back-up light switch on the
transmission, see Section
7.
CENTER HIGH-MOUNTED STOPLIGHT
Fig. 8B-7
Assembly Replacement
Remove or Disconnect
1. Spoiler (see Body Service Manual, Section 7H)
2. Four nuts from assembly
3. Stoplight assembly
Install or Connect
1. Stoplight assembly
2. Four nuts
3. Spoiler
Bulb Replacement
Replacement Bulb: Trade No. 577, 21
Candlepo wer
Remove or Disconnect
1. Two screws from lens
2. Lens
3. Bulb from socket
1. LAMP ASSEMBLY
2. SCREW($) 3. BULB
4. STUD8 ON SPOILER 5. WIRE HARNESS
Fig. 8B-1 Center High-Mounted Stoplight
Install or Corrnect
1. Bulb into socket
2. Lens
3. Two screws
FOG LIGHTS
Figs. 8B-2 and 88-3
Assembly or Bulb Replacement
Replacement Bulb: Trade No. H-3

INSTRUMENT PANEL, GAGES & CONSOLE 8C-'I
SECTION 8C
NSTRUMENT PANEL, GAGES & CONSOLE
CONTENTS
General Description ................................... 8C-1
Instrument Panel and Gages ........................ 8C-1
Printed Circuit .......................................... 8C-1
Instruments ................................................... 8C- 1
Speed Sensors
............................ .. ............. 8C- 1
Pinion Gear
............................................. 8C-2
Photo Speed Sensor ................................ 8C-2
PM Generator ................... .. ...... ............... 8C-2
Speedometer ................................................ 8C-2
Mechanical ....................... .. .................... 8C-2
Quartz ........................ .. .......................... 8C-2
Digital .................... .. ...... ................. 8C-2
Fuel Gage .................................................... 8C-2
Temperature Warning Light ...................... 8C-3
Generator Warning Light ............................ 8C-3
Engine Oil Pressure Light ............................ 8C-3
"Service Engine Soon" Light ....................... 8C-3
Upshift Indicator Light .............................. 8C-3
Diagnosis .................... .. ........................... 8C-3
General Information .................................. 8C-3
Instrument Panel & Gages ...................... ..... 8C-3
On-Car Service ......................... .. ........... 8C-4
Instrument Panel Pad ................................... 8C-4
Instrument Panel Cluster ........................... 8C-4
Instrument Panel Carrier ............................. 8C-4
Headlight Switch .......................................... 8C-4
Console Mounted Switches and
Accessories
............................................... 8C-4
Console ......................................................... 8C-4
Speedometer .................................................. 8C-5
Illustra3ions ................................................. 8C-5
IP Pad ........................................................... 8C-5
IP Carrier ................................................... 8C-6
Instrument Cluster ....................................... 8C-6
Lower IP Covers ......................................... 8C-7
IP Trimplates ............................................... 8C-7
IP Hush Panels; with A/C .......................... 8C-8
..................... IP Lower Trim Pad (Console) 8C-8
Map Holder or Map Pocket ........................ 8C-8
IP Hush Panels; without A/C ..................... 8C-9
Radio Mounting ........................................... 8C-9
Subwoofer & Hatch Release
Switches/Covers ........................................ 8C- 10
Foglamp Switch/Cover ................................ 8C- 10
Oil Pressure and Temperature
Switches
..................................................... 8C-11
Heater/Ventilation/Defroster
Ductwork .................................................. 8C- 12
A/C and Defroster Ductwork ..................... 8C-13
Ram Vent System Ductwork ....................... 8C-14
Console Mounted Switches
&
Accessories ................................................. 8C- 14
Dash Insulators
............................................ 8C- 15
Heater Floor Outlet
..................................... 8C-15
................ Headlamp/Parking Lamp Switch 8C- 15
............. Dash Mounted Accessory Switches 8C- 15
GENERAL DESCRIPTION
INSTRUMENT PANEL AND GAGES
INSTRUMENTS
Instruments consist of fuel gage, temperature
The instrument panel on most cars is a sing,e unit indicator light, generator light, oil pressure indicator
design and all parts attach to the main instrument light, and speedometer. See Section 9F for optional
panel with clips and screws. To service the instrument Gages and tachometer. Service on instruments
panel and components see on-car service information, can be obtained through authorized repair stations.
However, knowledge of instrument circuit checks will
PRINTED CIRCUIT
All models are equipped with printed circuits
which supply current to most instrument panel lights
and instruments. These circuits are made of copper foil
which is die cut and bonded to a polyester base film
(usually mylar). The printed circuit electrical power is
supplied by a connector containing several wires, as
shown in the instrument panel wiring harness
installation instructions. The connector also helps
retain the printed circuit to the speedo cluster. The rest
of the circuit is retained by additional connectors (if
used) and snap-in
bulbs/sockets. For individual
printed circuit diagrams, see Section
8A-80/8 1/82/83,
'Instrument Panel'. help
in determining if operating difficulties lie in the
instrument itself or its related circuit.
Instruments have been designed for easy removal
by elimination of separate wiring. With the wiring
provisions integrated with the instrument panel wiring,
the instruments can be removed after removing the
trim and lens.
SPEED SENSORS
There are three speed sensors currently in use:
1. PINION GEAR; used in mechanical systems
2. PHOTO SPEED SENSORS; used in mechanical
systems
3. PM GENERATOR; used in electronic systems

INSTRUMENT PANEL. GAGES & CONSOLE 8C-3
tank only when ignition switch is turned to "ON" or
"ACCESSORY" positions.
When ignition is turned to "OFF" or "START"
positions, the pointer may come to rest at any position.
The letters
"E" and "F" on the fuel gage are used to
point out direction of indicator travel only.
TEMPERATURE WARNING LIGHT
The engine temperature warning light is
controlled by a thermal switch which senses engine
coolant temperatures.
When the ignition switch is turned to "START"
position, a test circuit is closed and the light will come
on to indicate whether the light is functioning properly.
It is important to note that with low boiling-point
coolants (such as plain water) the temperature light
may not come on even though the coolant is boiling.
GENERATOR WARNING LIGHT
The generator warning light, located in the
instrument cluster, should come on when the ignition
switch is turned
"ON" and engine is not running. If
not, either the bulb is burned out or wiring to generator
has an open circuit.
When the generator voltage output becomes
greater than the battery voltage, the
"GEN" light
should go out. This does not, however, indicate
whether the battery is being charged or if the voltage
regulator is functioning properly.
Checks of the charging system are covered in
Section 6D, 'Engine Electrical'.
ENGINE OIL PRESSURE LIGHT
The engine oil pressure warning light is mounted
in the instrument cluster and controlled by a pressure
operated switch located on the engine block. When the ignition switch is
in the
"run" or "start9' position, the
oil pressure light should come on. If not, the bulb is
burned out, there is an open circuit between the bulb
and the oil pressure switch, or there is an open circuit
between the oil pressure switch and the choke heater.
After the engine is running, the oil pressure light
should go out when the oil pressure reaches the correct
specification. If not an oil pressure problem, a faulty oil
pressure switch or an open circuit from the choke
heater fuse to the oil pressure switch is indicated.
"SERVICE ENGINE SOON" LIGHT
All cars have a "SERVICE ENGINE SOON"
light mounted in the instrument cluster. The
"SERVICE ENGINE SOON9' light should come on
during engine starting. The light may stay on
a short
time after the engine starts.
If the light comes on while
driving, service to the emission control system may be
required. See Section
6E and Section 8A-80,
'Instrument Cluster', for complete diagnosis and
wiring diagrams of the
""P;RVICE ENGINE SOON"
light circuit.
UPSHIFT INDICATOR LIGHT
If your vehicle has a manual transmission, there
may be an
''Upshift" light on the instrument panel.
This light is illuminated to indicate optimum shift
points throughout the range from optimum fuel
economy to optimum performance. When this light is
on, shift your transmission to the next higher gear
range if conditions permit. For fuel economy,
accelerate slowly and shift when the light goes on. For
performance, accelerate as desired and shift when the
light goes on.
Safe operation of the vehicle may require shifting
differently than indicated by the "Upshift" light to
adapt to weather, road or traffic conditions.
Downshifting one or more gears may be required
to keep the engine running smoothly or to maintain
satisfactory performance.
DIAGNOSIS
Diagnostic information for all instrument panel
electrical systems is found in Section
8A-80,
'Instrument Panel'.
CAUTION: When removing or
installing any electrical units,
disconnect the negative battery cable
to prevent possible short circuits
which could lead to personal injury
and/or property damage. When
replacing a speedometer or
odometer assembly, the law requires the
odometer reading of the replacement unit to
be set to register the same mileage as the
prior odometer.
if the same mileage cannot be
set, the
law requires that the replacement
odometer be set to zero and a label be
installed on the driver's door frame to show
the previous odometer reading and the date
of replacement.
GENERAL BNFORMATlOM
INSTRUMENT PANEL AND GAGES
The instrument panel is a single unit design and
and screws. To service the instrument panel and
all parts attach to the main instrument panel with clips components see Figs. 601 through 610.

8E -2 WINDSHIELD WIPER SYSTEMS F CARLINE
brush circuit (Fig. 12) is completed to the (+) 12 volts
DC source and the wiper motor runs at that particular
speed setting.
Moving the switch to the PULSE mode operates
the wiper motor intermittently and the delay can be
varied by moving the switch back and forth in the Delay
Mode. An instantaneous wipe can be obtained by mov-
ing the switch to the MIST position. If the switch is
pressed continually, a continuous wiping action will be
performed. See Figs. 14,
15, and 16.
DIAGNOSVC PROCEDURES
The following procedures assume that the service
technician has checked:
@ the continuity of circuit harness wiring,
@ that the wiper-motor assembly-to-dash
mounting hardware is tight,
circuit fuses, and
@ that the washer hoses are clear, not kinked,
disconnected or broken.
1. Apply a (+) 12 volt DC (source) voltage to wiper
connector pins as shown in Fig. 13. If the motor
runs in all operating modes
(LO, HI; PARK &
PULSE), perform the voltage and continuity wiper
switch tests as shown on Figs. 14, 15 and 16.
2. If the wiper motor does not run in any one or all
of the operating modes, refer to the Wiper-Washer
Motor Diagnostic Procedures Reference (Fig.
4).
WASHER PUMP
Check washer pump operation before removing
washer pump from the car. Disconnect (cover) wiring
harness connection to wiper cover connector. Then ap-
ply a
(+) 12 volt DC (source) voltage to wiper terminals
as shown on Fig. 17.
1. If washer pump motor does not run or does not
pump water, replace washer pump, See On-Car
Service procedures for "Washer Pump
Replacement.
' '
2. If washer pump motor runs and pumps water, the
problem is in the wiper switch. See Fig. 16 for
switch test procedures.
See Fig. 12 for wiper circuit diagrams.
WIPER MOTOR
Check motor operation before removing wiper as-
sembly from the car. Disconnect wiring harness from
wiper assembly before performing the following checks:
Fig. 3 Pulse Wiper Operation Chart

WINDSHIELD WIPER SYSTEMS - F CARLINE BE -11
IPER ASSEMBLY WIRING DIAGRAM IRING DIAGRAM STANDARD & STANDARDIWASH.OUTWIPE WIPER ASSEMBLY
ELECTRONIC
Fig. 12 WIS Wiper-Washer Circuit Diagrams
Install or Connect
1. New park switch assembly (standard switch has
no extra terminals. Pulse switch requires them).
2. FoIlow "Wiper Cover Replacement" procedure
carefully.
WIPER MOTOR REPLACEMENT
Remove or Disconnect
1. L.H. andR.H. wiper arms
2. Cowl cover
3. Wiper arm drive link from crank arm
4. Electrical connectors
5. Wiper motor attaching bolts
6. Wiper motor guiding crank arm through hole
Install or Connect
1. Wiper motor guiding crank arm through hole
2. Wiper motor attaching bolts
3. Electrical connectors
4. Wiper arm drive link to crank arm
5. Cowl cover
6. L.H. and R.H. wiper arms
WIPER TRANSMISSION
Fig. 19
Remove or Disconnect
1. Raise hood.
2. Right and left wiper arm and blade assemblies

RADIO SYSTEMS AND ANTENNAS 9A-3
antenna. Check radio reception in an area away from
reception. If reception is OK, problem exists with
electrical interferences. These include tall buildings,
antenna and/or its lead-in cable. If reception is still
metal structures, power lines, fluorescent lighting, and
poor, refer to Section
8A.
power tools. Tune to high and low ends of the dial on
both AM and FM checking weak and strong station
reception. If reception is OK, problem exists with
antenna and/or its lead-in cable. If reception is still
poor, refer to Section
8A.
Checking Lead-In Cables
Figure 2
Usually symptons of broken center conductor of
the lead-in cable will result in no AM and weak FM.
In case of continued reception or noise complaints,
always check the lead-in with an ohmmeter. The chart
and diagram shown in Figure
2 show readings which
should be obtained. When checking resistance,
cautiously wiggle the lead-in tip and cable. If the
readings shown in Figure
2 are not obtained, some
portion of the lead-in is intermittent and the lead-in
should be replaced.
CHECKING FIXED ANTENNAS
Unplug antenna lead-in at back of radio and plug
a test antenna into radio. Make sure test antenna base
is grounded to the car chassis and keep hands off of the
antenna (see "Testing for Good Grounds"). Check
radio reception in an area away from electrical
interferences. These include tall buildings, metal
structures, power lines, fluorescent lighting, and power
tools. Tune to high and low ends of the dial on both
AM and FM checking weak and strong station
less than 0.5'
less than 0.5
'On some long lengths
of lead-ins, such as power antennas,
capacitance is added in the tip. This results in a resistance
reading of approximately 100,000 ohms.
Fig. 2 Lead-In Cable Diagnosis
SERVICE PROCEDURES
RADIO AND SPEAKERS
STEREO CASSETTE TAPE PLAYER
NOTICE: All radios are the bridge audio type,
using two wires to each speaker. It is very
important when changing speakers or performing
any radio work to avoid pinching the wires. A
short circuit to ground from either wire will cause
damage to the output circuit in the radio.
Also, all Delco sound systems have ungrounded
speakers. Installing add-on tape players, CB
radios or other units which use the car speakers
may damage your Delco sound system. Please
consult your dealer in advance if you are
considering additions.
See On-Car Service for radio or front speaker
replacement. See Body Service Manual at end of
this manual for door or rear speaker replacement. Figure 4
Tape and Tape Player Care
Optimum performance can be maintained by
cleaning the internal tape head, capstan, and pinch
roller periodically (approx. each 100 hours of
operation). This can be done by inserting a nonabrasive
cleaning cassette in place of the music tape.
DO NOT USE silicone spray lubricants for
switch, plunger or tape head lubrication.
NO LUBRICANTS should be used since they
cause the player to operate improperly, especially
at extreme temperatures.
Do not bring any magnetized tools near the tape
head. If the head becomes magnetized, every
cassette played will be degraded.
Store cassettes away from extreme heat or direct
RADIO NOISE SUPPRESSION EQUIPMENT sunlight. Protect the open ends from dirt or damage;
store them in their original cases or other protective
Figure 3 cases. For best results, 120 minute tapes are not
recommended.
When installing a new radio, or when noise is a
When leaving the car, cassettes may be left in the
problem, ensure that radio suppression equipment is
tape player (tapes are either automatically ejected or
present and properly installed.
internally protected).

GENERAL INFORMATION - F STYLE 1 H-1
SECTION IH
GENERAL NFORMAT
NOTICE: The anti-theft label found on some major sheet metal, engines, and transmissions must be masked
prior to painting, rustproofing, undercoating, etc. The mask
must be removed following the above operations.
Failure to keep the label clean and readable may result in liability for violation of Federal Vehicle Theft Prevention
Standard, and subject the vehicle owner to possible suspicion that the part was stolen.
Lock Cylinder Coding
..................................... I H-1 Chip Resistant Plastisol Material .................... 1 H-8
...................................................... Lubrication 1 H-2 Flexible Exterior Plastic Parts ......................... 1H-9
Adhesive Body Side Moldings ......................... 1H-3 Metal Replacement Parts Finishing ................ lH-13
Waterleak Diagnosis and Repair ..................... 1H-3 Interior Plastic Trim Parts Finishing .............. 1H-13
.................................................... Anticorrosion Treatment ................................ IH-4 Special Tools I H- 14
LOCK CYL!NDER CODING o Check key operation in the lock cylinder.
KEY IDENTIFICATION AND USAGE
REPLACEMENT LOCK CYLINDERS
The lock cylinder keyway is designed so that
other model keys will not enter a current model lock
cylinder. Two noninterchangeable keys are used.
CB Square headed key is used in the ignition lock
cylinder.
o Oval headed key is used in all other lock
cylinders.
Key identification is obtained from the four
character key code stamped on the knockout portion
of the key head and an identification letter stamped on
the key shank. After the code number has been
recorded by the owner, the plugs should be knocked
out of the key head. From these numbers, the lock
combination can be determined by use of a code list
(available to owners of key cutting equipment from
equipment suppliers). If key code numbers are not
available from records or from the knockout plug, the
lock combination (tumbler numbers and position) can
be determined by laying key on diagram in Figure
1.
I POSITION LEVELS I
Fig. 1 - Key Code Diagram
CUTTING KEYS
Lock cylinders are available from service parts
warehouses. The new cylinder has a locking bar staked
in place. Tumblers are also available and must be
assembled into the cylinder.
ASSEMBLING AND CODING LOCK CYLINDERS
All Lock Cylinders Except Rear Stowage
Compartment
Tumblers for all locks are shaped exactly alike
with the exception of the notch position on one side.
As the key is inserted in the lock cylinder, tumblers are
lowered to the correct height so that notches on each
tumbler are at the same level. When the notches on all
six tumblers line up, the side bar is pushed into the
notches by two small springs. This allows the cylinder
to turn in its bore. Five types of tumblers are used to
make the various lock combinations. Each tumbler is
coded according to a number,
1 through 5, stamped on
its side.
Assemble (Figs. 2 and 3)
1. Determine tumbler numbers and arrangement.
a. With numerical
key code, use code list
provided by key cutting equipment supplier.
b. Without numerical
key code or without
code list, refer to Figure
1.
o Lay key on key code diagram. Be sure
key is outlined by diagram.
Determine special code from the code list or the
key code diagram (Fig.
1). 3.
o Cut a blank key to the proper level for each of six
tumbler positions.
4.
Start with position number one. Find
and record lowest level (tumbler
number) that is visible. Repeat for
each of the remaining five positions.
Starting with position one [open end or head of
cylinder), insert tumblers in their proper slots in
the order called for by the code (Fig.
2).
Pull side bar out with fingers so that tumblers will
drop completely into place.
Insert one tumbler spring above each tumbler.