1988 PONTIAC FIERO brake light

LIGHTING SYSTEMS AND HORNS 8B-I
SECTION 8B
NG SYSTEMS AND HORNS
CONTENTS
........................... GENERAL DESCRIPTION 8B-1
Exterior Lights
....................... ................... Back-up Lights .. 8B- 1
Center High-Mounted Stoplight .................... 8B-1
Exterior Light Monitor .................................. 8B-1
............................ .................... Fog Lights .. 8B-1
Front Parking/Turn Signal Lights ................ 8B-2
............................... Hazard Flashers .. ........ 8B-2 .................................................... Headlights 8B-2
License Plate Lights ..................................... 8B-2
Light Switch ............................................... 8B-2
............... Rear Tail/Stop/Turn Signal Lights 8B-2
Sidemarker Lights ........................................ 8B-2
Turn Signals .......................................... 8B-2
......................... Underhood Light ... ........ 8B-2
Horns .......................................................... 8B-3
....................................... ON-CAR SERVICE 8B-3
Exterior Lights
............................................. Back-up Lights 8B-3
Center High-Mounted Stoplight .................... 8B-3
Fog Lights .................................................... 8B-4
Front Parking/Turn Signal Lights ................ 8B-4
Hazard Flasher .............................................. 8B-5
....................................................... Headlights 8B-5
License Plate Lights ..................................... 8B-7
............... Rear Tail/Stop/Turn Signal Lights 8B-8
.......................................... Sidemarker Lights 8B-8
................... ............... Turn Signal Flasher .. 8B-9
......................................... Underhood Light 8B-9
Horns ................................................................. 8B-9
REPLACEMENT BULB
.................................... SPECIFICATIONS 8B- 10
The following information, previously shown in this section,
has been moved to the sections shown.
Back-up Lights Switch
............................. ... ............................................................................ 7
................................................................................................................................. Fuse Block 8A
Ignition Switch ........................................................................................................................... 3B
Interior Lights
................................................................................................................... 8A, 8C
Neutral Start Switch ..................................................................................................................... 7
Parking Brake Warning Switch
......................... ... .................................................................... 5
........................................................................ Seat Belt, Key and Headlight Warning Alarm 8A
Stoplight Switch .......................... .. ............................................................................................... 5
Windshield
Wipers/Washers .................................................................................................... 8E
GENERAL DESCRIPTION
The exterior lighting system includes the
headlights (and headlight motors to raise or lower the
headlights), front
parkinghurn signal lights, front
cornering lights, fog lights, rear
tail/stop/turn signal
lights, back-up lights, license plate lights, center
high-mounted stoplight, and the underhood light; it
also includes all associated wiring, controls and related
hardware for these lights.
BACK-UP LIGHTS - The back-up lights are
next to the rear license plate. They will come on when
the transmission is shifted to Reverse. On cars with an
automatic transmission, the back-up lights are
activated by the neutral start switch. On cars with a
manual transmission, they are activated by a separate
back-up light switch on the transmission. For more
information, see Section 7.
CENTER HIGH-MOUNTED STOPLIGHT-
The center high-mounted stoplight, in the center of the
rear spoiler, will come on whenever the brake pedal is
pushed down. The light is powered separately from the rear
tail/stop/turn signal
lights through a separate
circuit in the stoplight switch (see Section
8A).
EXTERIOR LIGHT MONITOR - The Driver
Information Center, on cars so equipped, also monitors
certain front and rear lights. When a bulb burns out,
the message
"FRONT LAMP" or "REAR LAMP"
will appear in the DIC display, and a light will come
on to indicate which bulb has burned out. For more
information, see Section
8A.
FOG LIGHTS -The fog light switches are to the
left of the steering column on the edge of the
instrument panel. To use the fog lights, first turn on the
headlights or parking lights. Then, push the middle
switch (with the fog light symbol) to turn on the fog
lights. Push the left
("OFF") switch to turn off the fog
lights.
The fog lights should not be used as a substitute
for the headlights.
Switching to high-beam headlights will turn off
the fog lights; switching back to low-beams will turn
the fog lights on again.

88-2 LIGHTING SYSTEMS AND HORNS
The fog lights must be aimed for proper
illumination of the road. Fog light
aim should be
checked: at least once a year; when a new light housing
is installed; or if service or repairs in the front end area
have (or may have) disturbed the fog light mountings.
FRONT PARKING/TURM SIGNAL
LIGHTS - Pushing either side of the instrument panel
switch will turn on the front parking lights. (Pushing
the left side of the switch will also turn on the
headlights.) When the ignition is on and the turn signal
lever is moved, the appropriate front parking light
flashes to signal a turn. Both lights will flash when the
hazard flashers are on.
If the driver's door is opened when the parking
lights are on, a warning tone will sound. For more
information, see Section
8A-77.
HAZARD FLASHERS - The hazard warning
flasher is part of the turn signal circuit. Pushing in the
button (on the right side of the steering column) will
cause the front and rear turn signal lights, and the front
sidemarker lights, to flash. Pull out the collar around
the button to turn off the hazard flashers.
The hazard flashers will work with the ignition
either off or on. When the hazard flashers are on, the
turn signals do not
work.
The hazard flashers will stop flashing and stay on
brightly if the brake pedal is pushed down.
HEADLIGHTS - The headlights are controlled
by the switch on the instrument panel (to the left of the
speedometer). They will come on whether or not the
ignition is turned on. Pushing the upper left side of the
switch turns on the headlights and causes the headlight
motors to raise the headlights. Pushing the bottom part
of the switch turns off the headlights, and they should
lower.
If the driver's door is opened when the ignition
is off and the headlights are on, a warning tone will
sound. For more information, see Section
8A-77.
Headlight low-beam and high-beam are
controlled by the turn
signal/multifunction lever on
the left side of the steering column. When the
headlights are on, pull the lever toward the steering
wheel until the switch clicks; the lights will change
from low-beam to high-beam, or from high-beam to
low-beam. An indicator light on the center instrument
cluster will come on when the high-beam headlights
are on.
The headlights must be aimed for proper
illumination of the road. Headlight aim should be
checked: at least once a year; when a new headlight
bulb is installed; or if service or repairs in the front end
area have (or may have) disturbed the headlights or
their mountings. The headlight bezels do not need to
be removed to aim the headlights.
Headlight focus is set when the sealed-beam unit
is made; no adjustment for focus is necessary or
possible.
Some state and local laws specify
requirements for headlight aim; these laws
must be followed.
LICENSE PLATE LBGHTS -A light above the
rear license plate will come on when the headlights or
parking lights are on.
LIGHT SWITCH - Most exterior lights are
controlled by the switch on the instrument panel, to the
left of the speedometer. Pushing the upper right part
of the switch turns on the front parking lights, the
taillights and the sidemarker lights. (It also turns on
the instrument panel lights.) Pushing the upper left
part of the switch turns on all these lights plus the
headlights. Pushing the bottom part of the switch turns
off all lights.
In some cases (such as going through a car wash),
it may be desirable to raise the headlights without
leaving the headlights on. To do so, push the upper
right part of the switch to turn on the parking lights.
Then, lightly push the upper right part of the switch;
the headlights will raise but will not turn on.
(Remember that the parking lights and taillights will
stay on.)
For more information on this switch (including
on-car service), see Section
8C. Also see Section 8C for
information on interior lights.
REAR TAlL/STOP/TURN SIGNAL
LIGHTS - The rear tail/stop/turn signal lights are
part of the same light assembly. Pushing either side of
the instrument panel switch turns on the taillights.
When the brake pedal is pushed down, the lights glow
brighter to serve as stoplights.
Moving the turn signal lever when the ignition is
on causes the appropriate rear lights to flash. (If the
brake pedal is held down and a turn is signalled, one
side will flash and the other will stay on brightly.)
All lights will flash when the hazard flashers are
on. However, if the brake pedal is pushed while the
hazard flashers are on, the lights will stop flashing and
stay on brightly.
SIDEMARKER LIGHTS -The front and rear
sidemarker lights will come on when the headlights or
parking lights are on. Both front and rear sidemarker
lights also have reflectors; they will shine when struck
by light, whether or not the car's lights are on.
If the headlights or parking lights are off when a
turn is signalled, the front sidemarker light will flash
in unison with the front turn signal light on the same
side. If the lights are on when a turn is signalled, the
front
sidemarker light and front turn signal light flash
alternately.
TURN SlG N ALS - The front turn signals are
combined with the front parking lights. The rear turn
signals are part of the rear
tail/stop/turn signal lights.
The turn signals work only when the ignition is on, and
the hazard flashers are turned off.
The turn signals are controlled by the turn
signal/multifunction lever on the left side of the
steering column. Moving the lever all the way up or
down (past the detent) will turn on the turn signals.
When the turn is completed, the lever will return to
neutral and the turn signals will stop flashing.
For changing lanes or shallow turns where the
steering wheel does not move far enough to cancel the
signal, move the turn signal lever only to the first
detent. When the lever is released, it will return to
neutral and the turn signals will cancel.
UNDERHOOD LIGHT - The underhood light
will come on when the hood is raised.

Adjust 2 . Filler panel 3 . Electrical connector
1 . Increase Current - Turn adjusting screw 4 . ~~l~/~~~~~
clockwise 5 . Horn
2 . Decrease Current . Turn adjusting screw
counterclockwise
Install or Connect
3 . Current adjustments should be made 1/4 turn
(90") at a time
Horn Assembly
Remove or Disconnect
1 . Six screws from filler panel behind front fascia on
driver's side 1
. Horn
2 . Bolt/screw
3 . Electrical connector
4
. Filler panel
5 . Six screws
Horn Relay
The horn relay is in the convenience center.
behind the instrument panel to the right of the steering
column
. To remove the relay. pull it straight out .
REPLACEMENT LIGHT BULBS
For exterior light replacement procedures. see the rest of this
section
. For interior light replacement procedures. see Section $A
and Section 8C .
EXTERIOR LIGHTS Trade No . ...................................................................................................................... Back-up Lights 1 156
Center
High-Mounted Stoplight ............................................................................................. 577
Front Barking/Turn Signal Eights ..................................................................................... 2057
Fog Lights
............................................................................................................................... H-3
Headlights ....................................................................................................................... H6054 ................................................................................................................ License Plate Lights 194
.................................................................................... Rear Tail/Stop/Turn Signal Lights 2057
Sidemarker Lights (Front and Rear) ...................................................................................... 194 ..................................................................................................................... Underhood Light 211
BNTERBOR LIGHTS Trade No .
......................................................................................... Air Conditioner/Heater Controls 194 .................................................................................................................. Ashtray & Lighter 194 .............................................................................................................. Cargo Compartment 561
................................................................................................ Cluster & Speedometer (Tach) 194 ..................................................................................................................... Console Ashtray 194 ............................................................................................................. Console Compartment 194
Courtesy Lights
..................................................................................................................... 194 ......................................................................................................................... Dome Light 561
Gear Selector Indicator
............................................................................................................ 74 .......................................................................................... Headlight High-Beam Indicator 194
Indicator Lights
..................................................................................................... Brake System Warning 194
With Gages
........................................................................................................................ 74
............................................................... Charging System Warning (except Rally Gages) 194 .................................................................................................................... Choke Warning
194
With Gages
........................................................................................................................ 74
...................................................................... Oil Pressure Warning (except Rally Gages) 194 ............................................................................................................ Seat Belt
Reminder 194
With Gages
.................................... ... ................................................................................. 74 ............................................................................................. Service Engine Soon Warning 194
With Gages
..................................................................................................................... 74 ............................................................ Temperature Gage Warning (except Rally Gages) 194
........................................................................................................................ Reading
Light 906 ............................................................................................................ Turn Signal Indicators 194

LIGHTING SYSTEMS AND HORNS 8B-11
2-HORN LEADS 3-SIDE MARKER
4-HEADLAMP
%-TURN SIGNAL PARK LAMP
6-HEADLAMP MOTOR RELAY
7-HEADLAMP MOTOR JUMPER
8 -HEADLAMP ISOLATION RELAY
9- BRAKE PRESS. WARNING SW.
10-TO
SIDE MARKER
11-HORNS
12-TO
HEADLAMP
13-ENGINE HARNESSCONNECTOR
14-BULKHEAD CONNECTOR
15-CONNECTOR END CAP
16-HEADLAMP MOTOR ISOLATION RELAY
Fig. 8B-1 1 Forward Light Wiring

98-2 CRUISE CONTROL
Fig. 1 Multi-Function Lever
e The Set Position - With the button switch
depressed and then released (car speed must
exceed the low speed limit point, and the
Off/On/Resume/Accel Switch must be in the
ON position) the cruise speed will be set at the
speed the car was at when the button was
released. Car cruise speed will be within
& 1 mph
of the actual speed at engaged speed. The system
will cruise until either the
Off/On/Resume/Accel Switch is moved to OFF,
the ignition switch is turned off, and/or the
Set/Coast Button is pushed in fully and held.
Pushing the brake pedal (or clutch pedal) releases
the cruise but not the resume capability.
The Coast Position - With the button switch
fully depressed, the driver can raise or lower his
speed. To increase speed, the driver can
accelerate to a new speed, fully depress the switch
and release the button. The controller "forgets"
the previously set speed. An increased control
speed can also be more easily set by the
Off/On/Resume/Accel Switch as previously
described. To decrease cruise speed, the button
switch is held in, disengaging the cruise system,
which allows the throttle to return to the idle
position. When the car has slowed to the aesired
cruise speed, releasing the switch will re-engage
the system.
e The "Tap-Down" Position - In order to do
this the cruise must be engaged and operating.
"Tapping-down" is done by quickly pressing and
releasing the
Set/Coast Button, or "tapping" the
button. Do not hold the button in the depressed
position or the system will go into the "coast"
mode. "Tap-down" is a function in which cruise
speed can be decreased by
1 mph increments (one
tap = 1 mph decrease).
The accelerator may be depressed at any
time
to override the cruise system.
Release of the accelerator will return the
car
te the previous set cruise speed.
NOTICE:
To keep the vehic:e under control, and
to prevent possible vehicle damage, it is not
advisable to use the cruise control on slippery
roads. It is not recommended to use the cruise
control in conditions such as on winding roads or
in traffic of heavy or varying volume. When
traveling down
a steeply graded hill, the cruise control
should be disengaged by depressing the
bralte pedal lightly. The transmission can then be
shifted into a lower gear range to help control
vehicle speed.
ELECTRONIC CONTROLLER (MODULE)
Figure 2
Fig. 2 Controller (Module)
The controller interprets the position of the servo,
the position of the control switches and the output of
the speed sensor. In response to these inputs, the
controller electrically signals the opening or closing of
the vent and vacuum solenoid valves in the servo.
The controller is usually mounted on the pedal
bracket, but is integral with the ECM on some models
with certain engines. For specific location, see the
On-Car Service portion of this section.
SERVO UNIT
Figure 3
The servo consists of a vacuum operated
diaphragm, a normally open solenoid valve to vent the
diaphragm chamber to atmosphere, a normally closed
solenoid valve to connect the diaphragm chamber to
the vacuum source, and a variable inductance position
sensor.
The servo incorporates a steel core which moves
within a coil. Its resulting variable inductance provides
a continuous (voltage) servo position signal to the
controller. This voltage signal is constantly compared
to the vehicle speed signal. This comparison
determines if the cruise system has corrected the speed
error or if additional changes are required.
The servo operates the throttle in response to
signals from the electronic controller as follows:
Steady Cruise State (system engaged and
operating)
- Both vacuum and vent valves are
closed or sealed. The servo has a constant vacuum
on the diaphragm and places no requirements on
the vacuum source, as vacuum is trapped in the
diaphragm chamber.
e Vehicle Losing Speed (due to steep grades or
driver wishes to increase speed by using the Accel
or 'tap-up' feature)
- The controller energizes the
vacuum solenoid to open the vacuum valve to the
vacuum source. This increases the vacuum level

CRUISE CONTROL 98-3
CUUM BRAKE
-VARIABLE INDUCTANCE
POSITION SENSOR
-VENT SOLENOID AND VALVE
(NORMALLY OPEN)
6-- STEEL CORE
Fig. 3 Servo Unit
in the servo to increase the throttle opening. The
vent remains closed.
e Vehicle Gaining Speed (due to steep grades
or driver wishes to decrease speed by using the
Coast or 'tap-down' feature)
- The controller
de-energizes the vent solenoid to open the vent
valve to the atmosphere. This reduces vacuum in
the servo and allows the throttle return spring to
decrease the throttle opening. The vacuum valve
remains closed.
When the cruise system is engaged and operating
(without any interference from the driver via the mode
control switches), no speed correction will be made
until the car varies approximately
+ - 1/2 mph from set
speed.
When the controller senses an over or underspeed
condition it will pulse the opening of the vent or
vacuum valve. The pulse will be repeated as required
until the speed correction necessary brings the car to
the set speed. From any set speed, under normal road
load conditions, the vacuum valve will remain in a
completely open position when vehicle speed has The
ignition is turned off.
SPEED SENSORS
VSS
Buffer Amplifier
Figure 4
Fig. 4 VSS (Vehicle Speed Sensor)
This device supplies the vehicle speed input to the
controller on some cars. The optic head portion of the
VSS is located in the speedometer frame. A reflective
blade is attached to the speedometer
cable/head
assembly. The blade spins like a propeller, with its
blades passing through a light beam from a
L.E.D. in
the optic head. As each blade enters the
L.E.D. light
beam, light is reflected back to a photocell in the optic
head, causing a low power speed signal to be sent to the
buffer for amplification and signal conditioning. This
amplified signal is then sent to the cruise controller.
P. M. Generator
Figure 5
dropped 5mph below set speed. Likewise, when vehicle
speed has exceeded
3 mph over the set speed, such as This
device supplies the vehicle speed input to the
down a steep grade, the vent will go into ,-onstant open ~0ntI-011er on some cars. Vehicle speed information is
position. provided
to the controller by a P. M. (permanent
magnet) generator driven by the transmission. The
The servo go into an 'Pen vent position output frequency of the P. M, generator is sent to the under the following conditions:
buffer, which amplifies and conditions the signal to the
@ When the brake (or clutch) pedal is depressed. controller.
a An open variable inductance position sensor coil
in the servo.
a A loss of electrical power to the system.

VACUUM SUPPLY
Tht vacuum to operate the Cruise Control servo
can come from: manifold vacuum connected straight
to the servo, from manifold through a vacuum storage
tank, or straight from a vacuum pump. For specific
vacuum routing, see On-Car Service.
ELECTRICAL AND VACUUM RELEASE
SWITCHES
These switches are used to disengage the cruise
control system. An electrical release switch mounted
on the brake pedal bracket (and clutch pedal bracket
on cars equipped with manual transaxle) disengages
the system electrically when the brake (or clutch) pedal is
depressed. This is done by interrupting the flow of
current to the controller. A vacuum release valve
mounted on the brake pedal bracket vents the trapped
vacuum in the servo to atmosphere when the brake
pedal is depressed, allowing the servo unit to more
quickly return the throttle to idle position. This is done
by routing a separate hose directly to the servo from
the normally closed vacuum switch. These two types
of switches will also sometimes be combined with stop
light switch, TCC switch, or other switches. For
specific usage and adjustment of these switches, see
On-Car Service.
ELECTRICAL HARNESS
For specific wiring and connector locations, see
Section
8A-34, 'Cruise Control'.
Improper operation can be caused by one or a
CRUISE SYSTEM SURGES t combination of mechanical, electrical and vacuum The servo and throttle linkages should operate problems. In resolving any cruise system operating
problem, first make a visual inspection. Check the freely
and smoothly. This linkage should be
system to ensure there are no bare, broken, or adjusted
as described in the On-Car Service
disconnected wires or any pinched, damaged,
-or portion of this section.
disconnected vacuum hoses. The servo and throttle
e Check hose routing for pinches, leaks or
linkage should operate freely and smoothly. The servo restrictions.
(See vacuum schematics in the
linkage should be adjusted as described in the On-Car On-Car
Service portion of this section).
Service portion of this section. See
Section
8A-34, 'Cruise Control'.
CRUISE SET SPEED HIGH OR LOW
Since any problem in this system is either
vacuum, mechanical, or electrical, the technician
should perform a few initial checks before turning to
Section
8A. This can be done by first eliminating a
vacuum or mechanical problem by starting the engine
and using finger to feel for source vacuum at the servo,
and by visual inspection of vacuum release valve,
throttle linkage, vacuum hoses, etc. If preliminary
inspection reveals no solution and the system is
inoperative, use the diagnostic information in Section
8A-34, 'Cruise Control'.
Several versions of a quick check instrument
similar to tool 5-34185 are available. This quick check
instrument is installed in place of the controller and
determines which part of the system has a problem.
Instructions on the operation of the instrument will be
provided with the unit. Check vacuum hoses for
proper routing,
restrictions or leaks. Adjust or replace as
required. (See vacuum schematics in the On-Car
Service portion of this section.)
e Check servo linkage for excess slack and adjust
as described in the On-Car Service portion of this
section.
s If no system problem is noted, replace the
electronic controller (module).
EXCESSIVE CRUISE SPEED LOSS ON HILLS
e Check hoses for vacuum leaks. (See vacuum
schematics in the On-Car Service portion of this
section).
e Determine if check valve is functional (where
applicable).
CRUISE TAP-UP & TAP-DOWN
If all other functions of cruise control are working
except "tap-up" and "tap-down" the controller
(module) is at fault.

MISCELLANEOUS ACCESSORIES 96-4
SCELLANEOUS ACCESSOR
General Description ................................. 9G-1
Rally Gages .................................................. 9G- 1
Tachometer ................................................. 9G- 1
Trip Odometer
............................................. 9G- 1
Electric Rear Window Defogger ................. 9G-2
Power Remote Control Rearview
Mirror ........................................................ 9G-2
Diagnosis .................................................... 9G-2
Rally Gages ............................................... 9G-2
Tachometer .................................... .... .... 9G-2
Electric Rear Window Defogger ................. 9G-2
Power Remote Control Rearview
Mirror ........................................................ 96-2
Dash and Console Mounted
Accessory Switches
................................. 9G-4
General Description .................................. 9G-4
Electronic Glare Control Mirror ................. 9G-4
On-Car Service ............................................. 9G-4
Rally Gages, Tach ....................................... 96-4.
Rear Window Defogger ............................ 96-4.
Power Remote Control Mirror .................... 9G-4
GENERAL BESCRIP"T0N
RALLY GAGES
Figure I
The Rally Gage option, available on most models,
consists of an engine water temperature gage, an oil
pressure gage and a voltmeter.
These gages are incorporated into the instrument
cluster and replace the standard warning lamps. The
water temperature and oil pressure gages are
electrically operated from sending units mounted in the
cylinder head and oil filter base respectively. The
voltmeter registers regulated voltage, providing an
indication of the charging system's ability to keep the
battery charged. Continuous readings in either the high
or low voltage red bands can indicate improper voltage
regulation, broken or slipping alternator belt,
a shorted
alternator diode
or a defective battery. Readings in the
yellow band are normal with the engine idling or for
short periods after long engine cranking. However,
continuous readings in the yellow band can indicate
faulty operation. See Section
8A for diagnosis.
TACHOMETER
Figure 2
The tachometer indicates speed of the engine in
revolutions per minute (RPM). The engine can safely
be operated up to a maximum RPM as indicated by the
start of the red bar. Engine operation with tachometer
readings in the red area can lead to serious engine
damage.
Due to its dual-coil design, the tachometer may
not return to zero when the ignition
is turned oft: This
is
a normal condition and should not be diagnosed as
a problem in the tachometer.
TRIP ODOMETER
The trip odometer can be reset by twice fully
depressing the push button located on the right side of
the speedometer cluster. The first depression shows all
zeroes, and the second locks them in position. Both
depressions must be done to avoid possible half cycling
I -SERVICE ENGINE SOON
2-BRAKE WARNING LIGHT
3-CHOKE WARNING LIGHT
4-VOLTMETER
5-COOUNT TEMP. GAGE
6-FUEL GAGE
7-SEAT BELT LIGHT
8-OIL PRESSURE GAGE G20003 9G
Fig. 1 Rally Gages - Typical
of the trip odometer. A slow, steady push should be
used to avoid damage to the internal mechanism.
Do not reset the odometer with the
vehicle in motion. Damage to the odometer
may occur.
The trip odometer does not affect service
procedures for speedometers listed in Section
8C.