1988 PONTIAC FIERO lights

HORNS
TROUBEESHOOTlNG HINTS
Try the following checks before doing the
System Diagnosis.
1. If the Horns do not sound at all, check the
CTSY Fuse by operating the Cigar Lighter.
2. If only one Worn sounds, check the DK GRN
(29) wire and the suspect Horn.
Go to System Diagnosis for diagnostic tests.
SYSTEM DIAGNOSIS
Diagnostic steps for the symptoms listed in
the following table are listed after the table.
SYMPTOM TABLE
A: The Horns sound continuously
B: None of the Horns sound
A: THE HORNS SOUND
GONTlNUOUSLY
COMPONENT LOCATION Page-Figure
.............. Convenience Center Behind IIP, to
right of steering column. ........ 201-10-A
..................... ...... Fuse Block. Behind LH side
of I/P, belour light switch. 201-10-A
.................... Horn Switch Below
steering wheel hub
....................... Slip Ring Below
steering wheel hub
................ el00 (42 cavities) LH front of dash, left of brake master cylinder .. 201- 0-A
................ C210 (11 cavities) Behind IIP, on
RW lower side of steering column. 201- 9-A
.......................... S203. IIP harness, behind instrument cluster. ........ 201-10-8
B: NONE OF THE MORNS SOUND
(TABLE a,
Connect: TEST LAMB
IiENcE CENTER
I Condition:
a Horn Relay disconnected
Connect
Between I ","d::r I For Diagnosis
A (ORN) &
Ground
B: NOME OF THE HORNS SOUND
(TABLE 21
Horn Switch: ON
Jumper
Between
Test
Lamp lights
(Continued on next page)
See 1
See 2 A (ORN) &
B (BLK)
If all the results
are correct, go to Table 2.
1. Cheek the ORN (40) wire for an open (see
schematic).
2. Check the BLK (28) wire and the Horn
Switch for an open (see schematic).
Test
Lmp lights

BRAKE VVARNlNG SYSTEM
TROUBLESHOOTING HINTS
0 Try the following checks before doing the
System Diagnosis.
Check the GAGES Fuse and PNKIBLK
(39) wire by observing the VOLTS or
SERVICE ENGINE SOON Indicator with
the Ignition Switch in RUN and the engine
OFF.
0 Go to System Check for a guide to normal
operation.
0 Go to System Diagnosis for diagnostic tests.
SYSTEM CHECK
Use the System Check Table as a guide to
normal operation.
e Refer to System Diagnosis for a list of symp-
toms and diagnostic steps.
SYSTEM CHECK TABLE
RUN position to
BULB TEST
COMPONENT LOCATION Page-Figure
.................. Brake Fluid Level Switch. ......... Below brake fluid reservoir 201-16-A
..................... Fuse Block. Behind
LH side of IIP, below light switch. ...... 201-10-A
................. Ignition Switch. Behind IIP, on
top side of steering column ...... 201- 9-A
Parking Brake Switch.
............ In console, at base of parking brake ........... 201-12-D
................... Release Relay Taped
to IIP harness, behind RH side of IIP. .... 201-13-A
................ (2100 (42 cavities) LR
front of dash, left of brake master cylinder .. 201- 0-A
........................... S204. IIP harness, behind instrument cluster. ........ 201-10-A
.......................... ............... S228. IIP harness, above Fuse Block. 201-10-A
SYSTEM DIAGNOSIS
0 Diagnostic steps for the symptorns listed'in
the following table are listed after the table.
A: BRAKE INDICATOR REMAINS ON
WITH THE
IGNITION SWITCH IN
RUN AND THE PARK BRAKE OFF
(TABLE
1)
SYMPTOM TABLE
A BRAKE Indicator remains on with the
Ignition Switch
in RUN and the park
brake off
B BRAKE Indicator lights with the park
brake applied, but does not light when
brake fluid level is low
C BRAKE Indicator does not light at all
D BRAKE Indicator lights with the Igni-
tion Switch in BULB TEST, but does not
light when the park brake is applied
E BRAKE Indicator lights with the park
brake applied, but does not light when
the Ignition Switch is in BULB TEST
Refer to System Diagnosis when a result is
not normal. Disconnect:
CONNECTOR
At: BRAKE FLUID LEVEL SWITCH
Conditions:
0 Ignition Switch: RUN
0 Park Brake: OFF
Pressure Warning
If the result is correct, refer to Section
5 to
test the Brake Hydraulic System.
Replace the Brake Fluid Level Switch if
the Brake Hydraulic System is OK.
1. Go to Table2.

BRAKE WARNING SYSTEM I:
A: BRAKE INDICATOR REMAlNS ON
WITH THE lGNlTlON SWITCH IN
RUN AND THE PARK BRAKE OFF
(TABLE
2)
Disconnect: CONNECTOR I
At: PARKING BRAKE SWITCH
Conditions:
0 lgnition Switch: RUN
0 Park Brake: OFF
Disconnect
I Correct Result I For Diagnosis
Parking Brake
connector not light
If the result is correct, checklreplace the
Parking Brake Switch
1. Check the Ignition Switch for a short to
ground in the RUN position. If Ignition
Switch is good, check TANIWHT
(33)
wires for a short to mound.
B: BRAKE INDICATOR LIGHTS WITH 6: BRAKE INDICATOR DOES NOT
THE PARK BRAKE APPLIED, BUT
LIGHT AT ALL
DOES NOT
LIGHT WHEN BRAKE
FLUID LEVEL IS LOW
1. Check Indicator bulb, TANIWHT (33)
Connect: FUSED JUMPER
At: BRAKE FLUID LEVEL SWITCH
CONNECTOR
Conditions:
lgnition Switch: RUN
0 Park Brake: OFF
Connect
Between
Brake Fluid
Level Switch
Connector
&
Ground
If the result is correct, checklreplace the
Brake Fluid Level Switch.
1. Check TANIWHT (33) wire for an open.
Correct Result
Brake
Warning
Indicator lights
For Diagnosis
See 1

BRAKE WARNING SYSTEM
H CONNECTOR
epair TAN/WHT (33) wire for
D: BRAKE INDICATOR LIGHTS WITH E: BRAKE INDICATOR LlGHTS WITH
THE IGNITION SWITCH IN BULB THE
PARK BRAKE APPLIED, BUT
TEST, BUT DOES NOT
LIGHT WHEN DOES
NOT LIGHT WHEN THE
THE PARK BRAKE IS
APPLIED IGNITION SWITCH IS IN BULB TEST
At: IGNITION SWITCH CONNECTOR 61
If the result is correct, check/replace
the Ignition Switch.
1. Checklrepair TAN/WHT (33) wire for
ClRCUlT OPERATION
Battery voltage is applied to the BRAKE
Warning Indicator when the Ignition Switch is
in RUN, BULB TEST, or START. Three
switches are connected to the BRAKE Warn-
ing Indicator. When any one of these switches
closes, ground is provided and the Indicator
lights.
The Ignition Switch provides a ground when
it is in the BULB TEST and START posi-
tions. The BRAKE Warning Indicator lights.
The Parking Brake Switch provides a
ground when the park brake is applied. The
BRAKE Warning Indicator lights to alert the
driver.
The Brake Fluid Level Switch closes to light
the
BRAKE Warning Indicator when there is
low brake fluid in one of the two hydraulic brake
systems. This could be caused by a leak in one of
the brake lines. The switch can be reset to
an
open condition by refilling the reservoir. This
can only be accomplished after the faulty sys-
tem has been repaired.

DEFOGGER
TROUBLESHOOTING HINTS
e Try the following checks before doing the
System Check.
1. Check the PWR ACC Circuit Breaker by
operating the Power Door Locks or Power
Seats (if equipped).
2. Check the Gages Fuse by observing that the
Instrument Cluster Lights.
3. Check ground 6200 by observing that the
Cigar Lighter operates normally.
4. Check that the connectors on the Defogger
and the Defogger Timer-Relay are properly
mated.
5. If one or more of the grid lines do not heat,
refer to the Body Service Manual (Section
2) for repair procedures.
e Go to System Check for a guide to normal
operation.
a Go to System Diagnosis for diagnostic tests.
COMPONENT LOCATION Page-Figure
............ ............. Defogger Timer-Relay Behind
RH side of IIP, near ECM 201-1 1-D
..................... Fuse Block. Behind LH side
of I/P, below light switch. ...... 201-10-A
.................. 6201 (1 cavity) LH
shroud, near center access hole
.......................... 6200 Behind IIP, left of steering column ............ 201-10-16
.......................... 6322 Rear of car, near RH hatch support bracket. .... 201-15-D
.......................... S204. IIP harness, behind instrument cluster. ........ 201-10-A
.......................... S205. IIP harness, behind instrument cluster. ........ 201-10-A
.......................... S233. IIP harness, above Fuse Block. ............... 201-10-A
.......................... S327. Defogger harness, behind LR side of rear seat
SYSTEM CHECK
e Use the System Check Table as a guide to
normal operation. Refer to the diagnosis
given if other results occur. The actions must
be
pedormed in the order shown.
Tests follow in System Diagnosis.
SYSTEM CHECK TABLE -- -
ACTION NORMAL RESULT FOR DIAGNOSIS OF OTHER RESULTS
1. Turn the Ignition Switch to RUN, and de-
press the Defogger Control Switch.
2. Depress the Defogger Control Switch again
3. With the Defogger ON, depress the Defog-
ger Control OFF Switch
I
A. The switch button returns to the rest posi-
tion, and the ON Indicator in the center of the
Defogger Control lights
B. The Defogger grid removes fog from the
rear window
C. The ON Indicator and the Defogger turn
off after approximately
10 minutes
The ON Indicator and the Defogger turn on
After approximately
5 minutes, they turn off
again
The ON Indicator and the Defogger turn OFF Do
Test A
Do Test B
Do Test D
Replace the Defogger Timer-Relay
Do Test B
(Continued on next page)

DEFOGGER
r If all the voltages are correct, and the
Defogger still does not operate properly,
do Test D.
1. Check the PNK/BLK (39) wire for an
open (see schematic). If the wire is OK,
check the Gages Fuse.
2. Replace the Defogger Control.
3. Check the PPL/WHT (293) wire for an
open (see schematic). If the wire is OK,
do Test B.
4. Check the INST LP Fuse. Check the
GRY
(8) wire for an open (see
schematic).
5. Check the BLK (150) wire for an open
(see schematic). Check that ground
6200 is clean and tight. Replace Panel
Light if wire and ground are OK.
D: DEFOGGER TEST
With the Ignition Switch in RUN, and the
Defogger Switch pressed
ON, connect one lead
of a test lamp to ground. From inside the car,
lightly touch the other lead to each grid line,
and slowly move it along the length of the grid.
The brilliance of the test lamp bulb should
increase as the test lamp is moved from left
(Passenger's side) to right (Driver's side).
0 If the test lamp does not light along any one of
the grid lines, check
PPLIWHT (2931, PPL
(192) and BLK (192) wires to the Defogger
Control for an open
(see schematic). If OK, do
Test
E.
If the test lamp bulb shows full brilliance at
both ends of the grid, check the BLK
(1 50)
wire for an open to ground (see schematic).
e If the test lamp suddenly lights as it is moved
along the grid, a break in the continuity of the
grid line exists. Refer to the
GM Body Service
Manual for grid line repair procedure.
E: DEFOGGER LAMP TEST
CH SUPPORT ARM
Ignition Switch: RUN
LH Hatch
Support Arm
(Braided Test
Lamp
lights See
1
Wire) &
Ground
(see
schematic)
(Continued in next column) (Continued
from previous column)
See 2
Arm
(Braided
Wire) (see
schematic)
I
If all the results are correct, refer to the
GM Body Service Manual Section 2 for
grid line repair.
1. Do Test B.
2. Check the BLK (150) wire for an open
(see schematic). Check that Ground
6322 is clean and tight (see schematic).
CIRCUIT OPERATION
With the Ignition Switch in RUN, voltage
is applied to the Defogger Control. When the
Defogger Control Switch is pressed ON, volt-
age is then applied to the Defogger
Timer-
Relay. The contact closes which provides volt-
age to the ON Indicator and the Defogger.
The rear window will become warm to remove
the fog from the surface of the window.
The contact in the Defogger Timer-Relay
will stay closed until the Defogger OFF
Switch is pushed, or the timer cycle is
complete.
(Continued on next page)

AIR CONDITIONING: BLOWER CONTROLS
C67, ELECTRONIC
(Continued from previous page)
GRNIBLK (990) wire. If wire is good, do
Test
E.
5. Check for open in BRNNHT (64) wire. If
wire is good, do Test
E.
6: A/C CONTROL HEAD LED AND PANEL
LIGHT TEST
Measure: VOLTAGE
At:
A/C CONTROL HEAD CONNECTORS
(Connected)
Conditions: Ignition Switch: RUN
@ AIC Mode: VENT
* Light Switch: PARK
Light Dimmer Setting:
Full Brightness
I (GRY) & I Battery / See 2 1 Ground
Measure
Bemeen
T (BRN) C1 &
Ground
Light Dinimer Setting: Minimum
Brightness
Correct
Voltage
Battery
If voltages are correct, but Panel Lights
or LED Indicators do not light or dim,
replace the
AlC Control Head.
1. Check BRN (9) wire for an open.
For
Diagnosis
See 1
(GRY) '
Ground
61. If Blower Switch Indicator does not light,
check LT GRN (991) wire for an open. If
wire is good, replace
AlC Control Read.
* If any individual LED Mode Indicator does
not light, replace
AlC Control Head.
CIRCUIT OPERATION
The Blower Motor is a variable speed motor
which runs at a speed proportional to the
applied voltage. The higher the voltage applied
to the motor, the faster the speed.
When the Ignition Switch is
in RUN, battery
voltage is applied to the Low Blower Relay
through the
NTR-AIC Fuse.
With the Mode Selector in OFF, the Low Blower
Relay coil is grounded through the GRY wire and
the
A/C Control Head. The relay operates, its con-
tacts open, and the voltage to the Blower Switch
is removed. No voltage is supplied to the Blower
circuits. When any other mode except OFF is se-
lected, the Low Blower Relay is deenergized and
voltage is applied to the Blower Switch and
Blower Resistors.
With the Blower Switch in LO, voltage is
applied through
all Blower Resistors to the con-
tacts of the Blower High Speed Relay, and the
Minimum
Panel Light Voltage
- -
Blower Motor. The blower runs at low speed.
As the Blower Switch is moved through posi-
tions
M1 and M2, the switch bypasses some of the
Blower Resistors allowing more voltage to be ap-
plied to the Blower Motor which will increase its
speed.
See
3
When
the Blower Switch is in HI, voltage is
applied through the ORN (52) wire to the coil of
the Blower Nigh Speed Relay. The Blower Nigh
Speed Relay operates, removing the Blower Re-
sistors from the circuit.
Battery voltage is then applied directly to the
Blower Motor through the relay contacts and
the motor runs at maximum speed.
The battery voltage at
t
Control Read is also applied to the Blower
Switch Indicator and the Mode Selector Indica-
tors through the LT GRN (991) wire and Mode
Selector Switch. When the light switch is
turned to the PARK or HEAD position, bat-
tery voltage is applied to terminal T of the
AIC
Control Head which enables the Solid State
dimmer. The brightness of the LED Indicator
will then be det
terminal R. The volt
trolled by the panel
sets the brightness level of the panel lights and
LED Indicators in the
AIC Control Head.
1 2. Check GRY (8) wire for an open. I
3. Go to 8A-12, Light Switch Details for
diagnosis.

WARNINGS AND ALARMS: CHIMES
TROUBLESHOOTING H lNTS
* Try the following checks before doing the
System Check.
1. Check the STOP HAZ Fuse by observing
the Hazard Lights Operation.
2. Check the GAGES Fuse by observing the
BRAKE Warning Indicator with the Park
Brake applied and the Ignition Switch in
RUN.
3. Check 6200 by operating the Cigar Lighter.
4. If the FASTEN BELT chime reminder and
indicator operate continuously, replace
Audio Alarm Assembly.
5. If the Park Lights are operating normally
and only the Lights-On reminder operates
incorrectly, replace the Audio Alarm Assem-
bly.
Go to System Check for a guide to normal
operation.
Go to System Diagnosis for diagnostic tests.
SYSTEM CHECK
* Use the System Check Table as a guide to
normal operation.
COMPONENT LOCATlON Page-Figure
Convenience Center
.............. Behind IIP, to right of steering column. ........ 201-10-A
Fuse Block.
..................... Behind LH side of IIP, below light switch. ...... 201-10-A
Ignition Key Warning Switch
...... Upper part of steering column
Seatbelt Switch. ................. In driver's seatbelt buckle
C210
(11 cavities) ................ Behind IIP, on RH lower side of steering column. 201-
9-A
6325 (1 cavity) .................. At LH door sill, base of center pillar
6200 .......................... Behind IIP, left of steering column ............ 201-10-A
S204. .......................... IIP harness, behind instrument cluster. ........ 201-10-A
S205. .......................... IIP harness, behind instrument cluster. ........ 201-10-A
S225. .......................... I/P harness, behind instrument cluster. ........ 201-10-A
S227. .......................... IIP harness, behind instrument cluster. ........ 201-10-A
SYSTEM CHECK TABLE
ACTION
Sit in the driver's
seat and close the
driver's door
Turn the Ignition
Switch to RUN
Do not buckle the
seatbelt
NORMAL RESULT
A slow chime alarm
sounds
The FASTEN
BELTS Indicator
lights in the
Instrument Cluster
The chime stops and
the indicator shuts
off after 4 to
8
(Continued from previous column)
buckle
seatbelt
ignition, open the
LH front door
I seconds
(Continued in next column)
(Continued on facing page)