1988 PONTIAC FIERO lights

TROUBLESHOOTING HINTS
* Try the following checks.
Check
GTSY Fuse if none of the Interior Lights
operate.
DomeIReadinglCourtesy Lights
1. If the PanelIInterior Light Control does not op-
erate the Interior lights but the lights turn on
with any door open, check the Light Switch,
WBT (156) and BLK (150) wires for continuity
(see schematic).
2. If the Interior Lights do not come on with
only one door open, check the
WNT (156)
wire and suspect Door Jamb Switch for con-
tinuity.
Repairlreplace as necessary.
3. If the Dome Light comes on but the Reading
Light(s) do not, repairlreplace the Reading
Light(s) as necessary.
4. If the Dome and Reading Lights do not light
but the
RN and LII Courtesy Lights do,
check connection at
C206 and related wiring
(see schematic).
5. If the Dome Lights do not light when the
Panel Interior Light Control is turned to ON
but do light with any door open, check con-
nection at 6206
and related wiring for con-
tinuity (see schematic).
6. If the RN and LN Courtesy Lights do not
light with any door open but do light when
the Panel Interior Light Control is turned
ON, check related wiring for continuity (see
schematic).
7. If only one light does not operate, check bulb,
socket and related wiring (see schematic).
COMPONENT LOCATION Page-Figure
..................... Fuse Block. Behind
LN side of IIP, below light switch. ...... 201-10-A
................. C206 (2 cavities) Behd IIP, at LH shroud
................ C238 (12 cavities) LH shroud, ahead of center access hole. ........ 201-11-C
.......................... ............ 6200 Behind IIP, left of steering column 201-10-A
.......................... ................. 6302 Center of windshield header. 201-15-E
.......................... 63 19 In cargo compartment, behind center of end
................................... panel 201-17-D
.......................... S203. IIP harness, behind instrument cluster. ........ 201-10-A
.......................... S205. IIP harness, behind instrument cluster. ........ 201-10-A
.......................... ............ S237. I/P harness, behind LH side of IIP 201-10-A
8. If the Courtesy Lights do not turn off, check
the Panel Interior Light Control, Door Jamb
Switches and
WBT (156) wires for a short to
ground.
Glove Box Light GonsoleICigar Lighter
1. If the Glove Box Light does not light but the
Cigar Lighter works, check the connector,
ORN (40) wire,
BLK (150) wires, and switch
for continuity. 2. If
only the Cigar Lighter does not operate,
check the element for corrosion or damage.
Also check the ORN (40) and BLK (150) wires
to their connector and connector for continuity.
Replace the Cigar Lighter
Assembly if the ele-
ment, the wires, and connector are good.
Cargo Compartment EIgM
If only the Cargo Coqartment Light does
not operate, check the Cargo
Coqartment
Light Switch, connector 6238, ORN (40) wire,
WHT (156) wire and BLK (150) wires for con-
tinuity (see schematic).
Repairlreplace as neces-
sary-

INTERIOR LIGHTS
interior Lights and Cigar Lighter
Voltage is applied at all times through the
CTSY Fuse to the coqonents in the circuit.
The Glove Box Light, Dome Reading Lights,
and Cigar Lighter each use separate switches.
The
LH and RH Courtesy Lights and the Dome
Light can be turned on by closing the Panel
Interior Light Control, or by opening a door.
Cargo Compartment Light
Voltage is applied to the CTSY Fuse at all
times. With the Cargo Compartment Light
Switch closed, voltage is applied to the Cargo
Compartment Light.

- INTERIOR LIGHTS DIMMING
WITHOUT DIGITAL CLUSTER
.8 ORN 1240

INTERIOR LIGHTS DIMMING
TROUBLESHOOTlNG HINTS COMPONENT LOGATlON Page-Figure
a Try the following checks before doing the Fuse Block. ..................... Behind LN side of IIP, below light switch. ...... 201-10-A
System Check. Lights Monitoring Module. ........ Behind IIP, at base of steering column
................. ..... 1. Check the Light Switch by operating the Park RN
side of steering column, on IIP retainer 201-10-A
................ ........................ Lights. 6212 (12-cavities) Behind center of IIP 201-13-B -
.......................... ........................ 2. If none of the Instrument Panel Lights work, C218. Behind center of IIP 201-12-A
................. check the INST LP Fuse. C220 (2 cavities) Behind top LH side of IIP, near headlight switch. 201-10-A
............ 6200 .......................... Behind IIP, left of steering column 201-10-A
3. If a single light does not work, cheek the bulb ........ S204. .......................... IIP harness, behind instrument cluster. 201-10-A and the associated wires to the bulb. ........ S205. .......................... IIP harness, behind instrument cluster. 201-10-A
4. Check that 6200 is clean and tight. ............... S207. .......................... IIP harness, at head of console. 201-10-A
@ Go to System Check for a guide to normal S225. .......................... IIP harness, behind instrument cluster. ........ 201-10-A
operation. $274. .......................... IIP harness, at head of console. ............... 201-12-C
s Go to System Diagnosis for diagnostic tests.
SYSTEM CHECK SYSTEM DIAGNOSIS
Use the System Check Table as a guide to WITH DIGITAL CLUSTER
normal operation. r Perform
the follbking tests if the Interior
Lights dimming functions do not operate
properly.
SYSTEM CHECK TABLE
ACTION
Put the Light Switch
in the Park or
Head
Lamp position
Refer to System Diagnosis when a result is
not normal.
NORMAL RESULT
Instrument Panel,
Heater-AIC Panel,
and Radio Lights
turn on
Turn the Dimmer
Control through its
range
(Continued on facing page)
Lights brighten
in
one direction and dim
in the other

INTERIOR LIGHTS DIMMING
(Continued from facing page) B: REMOTE DIMMER TEST
Between I Result I Diagnosis
A: INTERIOR LlGHTS DIMMING TEST
Connect: TEST LAMP
At: FUSE BLOCK-HOT
SIDE OF lNST LP FUSE
Conditions:
@ ignition Switch: RUN
@ INST LP Fuse: REMOVED
r Light Switch: PARK
@ Dimmer Control: HI
cavity (DK
GRN)
& lights
Ground
Connect I Correct
@ Slowly turn Dimmer Control to LO
For
Ground
INST LP Fuse
cavity (DK
GRN)
&
r If all results are correct but Interior Lights
do not work, check the GRY
(8) wire for an
I open (see schematic). I
Test Lamp
dims
1. Check DK GRN (44) wire for an open. If
wire is good, do Test
B.
See 1
CONNECTOR
@ Light Switch: PARK
1. Check BRN (9) wire for an open (see
re is good, do Test C.
6: LlGHT SWITCH TEST
Connect: TEST LAMP
At:
LIGHT SWITCH CONNECTOR 62
(Connected)
Conditions:
@ Ignition Switch: RUN
@ Light Switch: PARK
r Dirnmer Control: HI
Connect
Between
D (PNWBLK)
& Ground
@ Slowly turn Dimmer Control to LO
Correct
Result
A (DK GRNI
WHT) &
Ground
I A (DK GRNI I Test Lamp / See 1
WHT) & dims
For
Diagnosis
Test Lamp
lights
I Ground I I I
See 1
Test Lamp
lights
If all results are correct but Interior Lights
do not dim, check the DK
GRNIWNT (744)
wire for an open. If wire is good, replace
Instrument Cluster.
1. Check the PNKIBLK (39) wire for an open.
See
2
1 2. Repairlreplace
the Light Switch. I
(Continued on next page)

INTERIOR LIGHTS DIMMING
(Continued from previous page)
WITHOUT DIGITAL CLUSTER
A: llUTERlOR LIGHTS DlMMlNG TEST
Connect: TEST LAMP
At: FUSE BLOCK-HOT
SIDE OF lNST LP FUSE
Conditions:
e ignition Switch: RUN
lNST LP Fuse: REMOVED
Light Switch: PARK
Dimmer Control: BRIGHT
Connect Correct
For
Between Result Diagnosis
INST LP Fuse Test Lamp cavity (DK See 1
GRN) & lights
Ground
I I @ Slowly turn Dimmer Control to DIM I
INST LP Fuse Test Lamp
cavity (DK See 1
1 GRN) & 1 dims 1 1
I Ground I I 1
If all results are correct but Interior Lights
do not work, check the GRY
(8) wire for an
I open (see schematic). I
1. Check DK GRN (44) wire for an open. If
I wire is good. do %st B.
B: REMOTE DIMMER TEST
At: REMOTE DIMMER CONNECTOR
1. Check BRN (9) wire for an open (see
2. Check DK GRNIWNT (844) wire for an
open (see schematic). If wire is good, do
C: LIGHT SWITCH TEST
Connect: TEST LAMP
At: LIGHT
SWITCH CONNECTOR 62
(Connected)
Conditions:
r Light Switch: PARK
a Dimmer Control: BRIGHT
Connect Correct For
Betvveen Result Diagnosis
(BRN) Test
Lamp
, &Ground lights See 1
1
A I I Test Lamp
lights I See 2 /
I Ground I I I
I Slowly turn Dimmer Contml to DIM I
dims
Ground
If all results are correct but Interior Lights
do not dim, check the DK
GRNIWNT (844)
wire for an open.
1. Check the BRN (9) wire for an open.
2. Repairlreplace the Light Switch.
CIRCUIT OPERATION
Voltage is applied at all times to the Light
Switch through the Tail Fuse. With the Light
Switch in
HEAD or PARK, voltage is applied
through the Light Switch, Remote Dimmer, and
INST LP Fuse to the various Instrument Panel
and Console Lights. The lights can be dimmed
using the rheostat in the Light Switch.

POWER WlNDOWS
(A: LH FRONT POWER WINDOW
SWITCH TEST continued from previous
.page) 6: WINDOW MOTOR TEST
. Check BLK (150) wire for an open (see
B: RH FRONT POWER WINDOW
SWITCH TEST
At: RM FRONT POWER WINDOW SWITCH
CONNECTOR (Connected)
I 0 lanition Switch: RUN I
s Ignition Switch: RUN
Operate associated Power Window
D (PNK) Test Lamp
& B (BLK) Lights See 2
0 Operate
RH Front Power Window
Switch UP and DN
C (LT BLU) ( Test Lamp ( See & A (TAN) lights
0 If all the results are correct, go to Test C.
1. Check PNK (76) wire for an open (see sche-
matic).
2. Check BLK (150) wires for an open (see
schematic).
3. Replace RN Front Power Window
Switch. With
the Ignition Switch in RUN, voltage is
applied through the
WDO Circuit Breaker and
the PNK and
PNKIWNT wires to the Power
Window Switches. With the LH Front Power
Window Switch in UP, voltage is applied
through the WDO Circuit Breaker, the
LN
Front Power Window Switch, and the DK BLU
wire to the LH Front Window Motor. The
Motor is grounded through the BRN wire and
the DN contacts of the LN Front Window
Switch to 6309. The motor runs and the
window goes up. Voltage is
similarly applied
with the RN Front Power Window Switch in
UP.
In DN, voltage is applied to each motor in the
opposite direction and the window goes down.

POWER DOOR LOCKS
IT
(Continued from previous page)
A: DOOR LOCK MOTOR TEST
At: SUSPECT DOOR LOCK MOTOR
CONNECTOR (Disconnected)
suspect Door Lock Motor.
1. Check the TAN (294) wire for an open
(see schematic).
2. Check the GRY (295) wire for an open
B: DOOR LOCK SWITCH TEST
(Continued from previous column)
See 2
If
all the voltages are correct, check the
LT BLU (195) wire and BLK (194) wires
for an open (see schematic).
1. Check the CTSU Fuse. Check the ORN
6: DOOR LOCK RELAY TEST [TABLE '11
Connect: TEST LAMP
At: DOOR LOCK RELAY CONNECTOR
61 (Disconnected)
A (ORN' Test Lamp
BLK) & See 1
1 Ground 1 lights
If the result is correct, proceed to Table 2.
1. Check the PWRIACC Circuit Breaker and
the
ORNIBLK (60) wire for an open (see
schematic).
(Continued in next column)
6: DOOR LOCK RELAY TEST (TABLE 2)
Connect: TEST LAMP
At: DOOR LOCK RELAY CONNECTORS
C1 & 62 (Connected)
Condition: Door Lock Switch: LOCK and hold
Move the Door Lock Switch to UN-
I LOCK and hold
C1: C (GRY)
Test See
3
(Continued on facing page)