1988 PONTIAC FIERO Service Repair Manual

HEADLIGHTS

TROUBLESHOOTING HINTS COMPONENT LOCATION Page-Figure
* Try the following checks before doing the Headlight Dimmer Switch. ........ Behind IIP, on LH upper side of steering column. 201- 9-A
System Diagnosis. el00 (42 cavities) ................ LH front of dash, left of brake master cylinder .. 201- 0-A
.... ............. 1. If Headlights on one side are on dimly, 6103 (Except VIN E)
On radiator support, behind LH headlights. 201-16-A
........... ................... check the ground on that side. 6103 (VIN E) RN inner fender panel, near battery 201- 3-B
2. If Hi Beams do not light, but the Hi Beam
Indicator lights, check LT
GRN (11) wire
for an open (see schematic).
3. If one Headlight doesn't work, check the
Headlight, connections, and wires to the
Headlight.
4. If the Headlights do not turn off, replace
the Light Switch.
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: All Headlights are inoperative or
intermittent
B: Lo Beams on both sides are inoperative
s and Hi Beam Indicator are
.... .......................... 6104 On radiator support, behind RH headlights. 201-16-A
............ 6200 .......................... Behind IIP, left of steering column 201-10-A
.... .......................... S107. Front lights harness, behind LH headlights. 201-16-A
.... .......................... S110. Front lights harness, behind RH headlights 201-16-A
.... .......................... S149. Front lights harness, behind LH headlights. 201-16-A
.... S150. .......................... Front lights harness, behind LH headlights. 201-16-A
........ S205. .......................... IIP harness, behind instrument cluster. 201-10-A
A: ALL HEADLIGHTS ARE
INOPERATIVE OR INTERMITTENT
(TABLE 1)
A: ALL HEADLIGHTS ARE
INOPERATIVE OR INTERMITTENT
(TABLE 21
Connect: TEST LAMP
At: LIGHT
SVVITCH CONNECTOR C1
(Connected)
Condition:
r Liaht Switch: HEAD
Connect Correct
Between Result Diagnosis
C (RED) Test Lamp
& Ground lights See 1
D
(YEL) Test Lamp
If both results are correct, go to Test B.
1 1. Check Fusible Link A and RED (2) wire
for an open (see Power Distribution).
Connect: FUSED JUMPER
At: LIGHT
SWITCH CONNECTOR C1
(Disconnected)
Conditions:
r Put a 15 amp fuse in the fused jumper
* Headliaiht Dimmer Switch: LO
I Connect 1 Correct ( or 1
Between I Indication 1 Diagnosis I I
I C (RED) & ( Heydlights I See D (YEL) ight
I Headlight Dimmer Switch: HI I
(Continued on next page

HEADLIGHTS
(Continued from previous page)
If results are correct, replace Light
Switch.
short to ground in wiring to
B: LO BEAMS ON BOTH SIDES ARE
INOPERATIVE OR HI BEAMS AND
Ell BEAM INDICATOR ARE
Connect: TEST LAMP
At: HEADLIGHT DIMMER SWITCH
CONNECTOR (Connected)
Conditions:
0 Light Switch: HEAD
0 Headlight Dimmer Switch: LO
Connect Correct For
0 If all results are correct, check wiring to
lights for an open.
1. Check YEL (10) wire for an open.
2. Replace Headlight Dimmer Switch.
CIRCUIT OPERATION
Voltage is applied to the Light Switch at all
times. The Light Switch includes a Self-Re-
setting Circuit Breaker. The Circuit Breaker
opens when the Headlight circuit draws too
much current. When the Circuit Breaker
opens, it interrupts the current flow. With no
current flow, the Circuit Breaker cools off and
resets automatically. When the Light Switch
is in
HEAD, the Headlight Dimmer Switch
directs voltage to either the Lo Beams or
Hi
Beams. The Hi Beam Indicator also receives
voltage along with the
Hi Beams.

HEADLIGHTS: FOG LlGHTS
DISTRIBUTION
FUSE
- BLOCK -
TO INSTRUMENT CLUSTER
TO C103 ON AND ClOO PIN A2 ON NEXT PAGE
NEXT PAGE TO
FOG LIGHT SWITCH
ON NEXT PAGE

HEADLIGHTS: FOG LIGHTS
TROUBLESHOOTING HINTS
r Try the following checks before doing the
System Diagnosis
.
1 . Check that the Headlights and Park Lights
work properly before troubleshooting the
Fog Lights
.
2 . If one Fog Light doesn't work, check the
Fog Light. connections. and wires to the
Fog Light
.
Go to System Diagnosis for diagnostic tests .
SYSTEM DIAGNOSIS
Do the following test if the
operate
.
-., U .
Fog Lights do not
COMPONENT LOCATION Page-Figure
Fog Light Relay
................. LH front of engine compartment. on fender .....
Fuse Block ...................... Behind LH side of IIP. below light switch .......
Fusible Link A (VIN E) ........... Lower RN side of engine. at Starter Solenoid ....
Fusible Link A (VIN F) (VIN 8) ..... Lower RH side of engine. at Starter Solenoid ....
Fusible Link A (VIN S) ............ Lower RH side of engine. at Starter Solenoid ....
Fusible Link D .................. Front lights harness. near kH side of dash ......
Fusible Link E ................... Front lights harness. near LH side of dash ......
Fusible Link 6 .................. Front lights harness. near LN side of dash ......
......... . er Switch Behind IIP. on EN upper side
of steering column
Remote
Dimmer ................. RH side of steering column. on IIP retainer ..... .
C100 (42 cavities) ................ LH front of dash. left of brake master cylinder ..
C103 (1 cavity) ................... In front lights harness. LH rear corner of engine
compartment
............................
C213 (3 cavities) ................. Behind LH side of IIP. near Light switch ........
6103 (Except VIN E) ............. On radiator support. behind LR headlights .....
6104 .......................... On radiator support. behind RN headlights .....
6200 .......................... Behind IIP. left of steering column ............
S105 ........................... Front lights harness. behind LH headlights .....
S107 ........................... Front lights harness. behind LH headlights .....
S110 ........................... Front lights harness. behind RH headlights ....
S150 ........................... Front lights harness. behind LH headlights .....
S165 ........................... Forward lights harness. LH front corner of
engine compartment
......................
S205 ........................... I/P harness. behind instrument cluster .........
S225 ........................... I/P harness. behind instrument cluster .........
S236 ........................... IIP harness. below light switch ...............

HEADLIGHTS: FOG LIGHTS
FOG LIGHTS DO NOT OPERATE CIRCUIT OPERATlON
The Fog Lights are controlled by the Light
Switch. They can be turned on with the Park
or Headlights on. With the Hi Beams on, the
Fog Lights go out.
The Fog Light Relay controls battery volt-
age to the Fog Lights. The Fog Light Switch
applies voltage to the relay coil. The relay coil
is grounded through the Hi Beam filaments.
When the Hi Beams come on, battery voltage
is at both sides of the relay coil. The relay and
the Fog Lights turn off.
At: FOG LIGHT RELAY CONNECTOR
(Disconnected)
1. Check the Fog Light Switch and BRN (9)
and BRNIWNT (909) wires for an open
(see schematic).
2. Check LT GRN (11) wire for an open.
3. Check Fusible Link G and RED/WNT (2)