1988 PONTIAC FIERO Service Repair Manual

- 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 WINDOWS
--- ------ *DO 1 FUSE LOCK CmT I- ! I {- BREAKER !
WOO 35AMP I L,-2 ,----- -I
3 PNK 76 1

POWER WINDOWS
TROUBLESHOOTING HINTS
s Try the following checks before doing the Sys-
tem Check.
1. If no windows operate, check the WDO Cir-
cuit Breaker by visual inspection.
2. If no windows operate, check that ground
6309 is clean and tight.
e Go to System Check for a guide to normal
operation.
e Go to System Diagnosis for diagnostic tests.
COMPONENT LOCNIOM Page-Figure
..................... ...... Fuse Block. Behind LH side
of IIP, below light switch. 201-10-A
................. ............. VVindow Motors In lower front corner of each door 201-18-A
................ ........ C238 (12 cavities) LH shroud, ahead of center access hole. 201-11-C
.......................... 6309 Below rear of console
.......................... S301. Crosscar harness, below LR front seat
SYSTEM DIAGNOSIS A: LH FRONT POWER WINDOW
e Do the tests listed for your symptom in the SWITCH TEST
Symptom Table below.
e Tests follow the Symptom Table.
SYSTEM CHECK SYMPTOM TABLE
* Use the System Check Table as a guide to
normal operation.
Refer to System Diagnosis for a list of symp-
toms and diagnostic steps.
SYSTEM CHECK TABLE
and DN from the
moothly, with no
EH Front Power
Window Switch
RH Front Window
RH Front Power
r Refer to System Diagnosis when a result
is not normal.
to splice S301 for an
open. If wire is OK,
perform tests A and
RH Front Power
Window does not Window Switch
CONNECTOR (Connected)
(A: LN FRONT POWER WINDOW
SWITCH TEST continued on next page)