light ISUZU TROOPER 1995 Workshop Manual

8-58 CHASSIS ELECTRICAL
HEADLIGHT AND FOG LIGHT
GENERAL DESCRIPTION
The circuit consists of the headlight, fog light, lighting switch, dimmer·passing switch, fog light switc~, high­
beam indicator,
lighting relay, tail relay and fog light relay. When the lighting switch is turned on by s~tting it
at the headlight position, the lighting relay is activated to turn on the headlight. The optical axis oft he hE ad light
can be turned up or down by operating the dimmer switch while the head light is on.
The passing switch is independent
of the lighting switch, and the optical axis ofthe passing light can bE turned
up only while the switch lever is pulled up and held in this state.
When the fog
light switch is turned on while the headlight on at low-beam, the fog light relay is acti ated to
turn on the fog light.
OPERATION OF THE CIRCUIT
BATTERY(+)
FOG LIGHT RELAY .--*-----1--,
1.~---g I
~
Wr
FOG rG LIGHT! '!r_., SW ,
FOG LIGHT "ON" (Only when dimmer• passing SW is at LO position) BATTERY(+)
BATTERY(+)
h~
I.A ~I
LIGHTING RELAY "ON" (When lighting SW is
ICb
at
headlight position)
HEADLIGHT
~· LO-HI
I
DIMMER• LO HI PASSING SW
I
.-~ ~J I I
I I
§D ~_. o ¢:!]
~-~ bt I I I I
I I 0 r--~: _____ ------
o;[X]E 0 o----~
r----------------
OFF
LIGHTING sw (HEADLIGHT
POSITION)
NOTE:
Arrow marks "c::::::>" indicate the direction of current
Fig. 8-77
J •

::!! CQ 00 I ....... 00
(
HEADLIGHT
HIGH
BEAM
INDICATOR
LIGHT
(METER)
RELAY:
FOG
LIGHT
RELAY
& FUSE
BOX

(FL-1,
F-4,
F-5, F-8,
F-12)
RELAY:
TAIL
"' "
.
RELAY:
LIGHTING
'"~
'
HEADLIGHT
(RH) FOG
LIGHT
(RH)
(
COMBINATION
SW
"',,,
HEADLIGHT
(LH)
!,--
FOG
LIGHTSW
C-16
(
;g ~ r-0 0 ~ 0 2
(') :I: )II (I)
(I) c;; m r­m ~ ::a 0 )> r-eo I m

('")
co
ill
~ (!]
11t
-
I
z
88
::0
iii

en
,
('")
0
5:
~ [I].,.
30B
~~
m
+
c
n
~ciJ~I~~
=i
:I:
FRT
FOG
LIGHT -
LH
)>
r;:;-n
11:::-1
0.85
v
f'-1
..
c
(J)
0.56
.r---
!!!
(J)
,
-)>
Cii
0.56
,..,..,
~
,.....,
I
lo
.,,
G)
m
~
g~
.....
::0
r-
or-
"'
!:-<
.. _
m
., ..
;:
)>
FRT
FOG
LIGHT
SW
J:
:e
n
....
z
s
-1
ILLUMINA TlON
0.5
RIG
J~~~ll~
0.85
G/R
CONTROLLER(3)
o
• RELAY;TAIL(4)
5W
~
::0
(TO PAGE
8-791
(TO PAGE
8-78)
:;;
n
.,
0.5Y/G
0.5Y/G
do
)>
~ ;;;
r-
-
0.85R,IL
:;:
2
~
..
w
!>
OJ
-;::
ill
8~
HIGH
BEAM
INDICATOR
j1!
~~
(METER
I
z:: ~m ~~ "'"' ~:;;
~~
~I
I
~~w
l.
RELAY ;
LIGHTING
0.85Y
.. ;::
fG1
~
...
3R,IB
3W
!W
-
~-
00 I
~o-J...I
u:::J
u;
Lll;;;
I
11-1
1-11
~I
I
'!> -u::.J-
---
1.25W
..
-
-
IJ -<
HEAD
LIGHT
-RH
~
e
1.25
R1Y
~
~
w
-
I~
ANTI
THEfT
0.3V/R
!
O.!V/R
RELAY;
CORNERING(11
CONTROI.LER(181
(TO PAGE 8-1081
(TO PAGE 8-2721
.. w
Of;
I
., .. I
ill
O.SR,IB
I
s;: ~
0.56
~I
; I
I ! I
I
I
I~
~
;=
~
0.3G
ILLUMINATION
LIGHTS
(TO PAGE
8-781
)
)
)
•

8-62 CHASSIS ELECTRICAL
DIAGNOSIS
QUICK CHART FOR CHECK POINTS ~ )-; '. ·'·• 1. Heaplight 1:·
~
Fuse Lighting Lighting Dimmer• Headlight c ~ble Passing bulb F-4
F-5 relay sw ha ness
T
(15A) (15A) sw LH RH
1-1. Both Headlights inoperative 0 0 0 b (1) (3) (4) 2)
1-2. Headlight on
the left (or 0 0 0
0 b right) side inoperative (1) ((1)) (2) ((2)) 3)
1-3. Headlights in low-beam 0 b inoperative (1) 2)
1-4. Headlights in high-beam 0 b inoperative
(1) 2)
1-5. Headlight beam does not 0 p
change (1) 2)
1-6. Headlights remain on 0 0 b when the lighting switch is
( 1) (2) 3) turned off
1-7. Headlights come on with 0 ~ the lighting SW at the
parking light position (1)
NOTE: Figure in parenthesis"( )" indicates the order of inspection.
2. Fog light
~
Fuse
Fog light Fog light Fog light Cc ble F-8 bulb
(15A) relay switch LH RH har ness Tr
2-1. (While the headlight is on in low-beam) 0 0 0 c ~ Both
fog lights are inoperative (1) (2) (3) ( )
2-2. (While the headlight is
on in low-beam) 0 0 CD Fog light on the left (or right) side is
( 1) ( ( 1)) ( ) inoperative
NOTE: Figure
in parenthesis"()" indicates the order of inspection.
~ -'
..

CHASSIS ELECTRICAL 8-63
1-1. BOTH HEADLIGHTS INOPERATIVE
• IS THE LIGHTING RELAY NORMAL? I
I
I I
YES I NO I
I
I
• IS [[I[] GROUNDED SECURELY? I REPLACE THE LIGHTING RELAY I
I
I
I
YES I NO I
I I
• IS THE DIODE NORMAL? J GROUND IT SECURELY I
I
I I
YES I NO I
I
I
• DISCONNECT THE LIGHTING SW CONNECTOR REPLACE THE DIODE J • IS THE BATTERY VOLTAGE APPLIED BETWEEN THE HARNESS
SIDE CONNECTOR 1 [[I[j AND GROUND?
I
I I
YES I NO I
I I
• REMOVE THE LIGHTING SW REPAIR A POOR CONNECTION AT THE CONNECTORS
• IS THERE CONTINUITY BETWEEN 1 [[I[] AND 7 ~WHEN OR AN OPEN CIRCUIT BETWEEN THE FUSUBLE LINK SETTING THE LIGHTING SWAT THE HEADLIGHT POSITION? FL-1 (80A) AND 1 ~
I
I I
I YES I NO I
1 I
REPAIR A POOR CONNECTION AT THE CONNECTORS OR AN REPAIR OR REPLACE THE LIGHTING SW I OPEN CIRCUIT BETWEEN THE HARNESS SIDE CONNECTOR 1WI] AND~ (GROUND) OF THE LIGHTING SW

8 -64 CHASSIS ELECTRICAL
1-2. HEADLIGHT ON THE LEFT (OR RIGHT) SIDE INOPERATIVE
• IS THE FUSE F-4 (15A) (OR F-5 15Al NORMAL?
I
I
YES I
I
• IS THE HEADLIGHT BULB ON THE LEFT (OR RIGHT)
SIDE NORMAL?
I
I
YES I
I
I
REPAIR A POOR CONNECTION AT THE CONNECTORS OR
AN OPEN CIRCUIT BETWEEN FUSE F-4 (15Al AND
3~(0R FUSE F-5 115Al AND 3WUI
I
I NO I
I
I REPLACE THE FUSE
I
I NO I
I
I REPLACE THE BULB
I
I
1-3. HEADLIGHTS IN LOW-BEAM INOPERATIVE
• REMOVE THE CONNECTOR DIMMER•PASSING SW (COMBINATION SW)
• WITH
THE SWITCH AT THE LOW-BEAM POSITION, IS THERE CONTINUITY BETWEEN THE SW CONNECTOR
TERMINALS
13[[I[jAND 16[[1[]
I
I
YES I
I
REPAIR A POOR CONNECTION AT THE CONNECTORS OR
AN OPEN CIRCUIT BETWEEN 13[[ll]AND 10~
I
I NO I
I
I REPAIR OR REPLACE THE DIMMER•PASSING S1tJ I

CHASSIS ELECTRICAL 8 .... 65
1-4. HEADLIGHTS IN HIGH-BEAM INOPERATIVE
• DISCONNECT THE CONNECTOR DIMMER•
PASSING SW (COMBINATION SWl
• WHIT THE SWITCH AT HIGH-BEAM, IS THERE
CONTINUITY BETWEEN THE SW CONNECTOR TERMINALS
15~AND16~7
I
I I
YES I NO I
I I
REPAIR A POOR CONNECTION AT THE CONNECTORS REPAIR OR REPLACE THE DIMMER•
OR AN BROKEN WIRE BETWEEN 15[[]IJAND 16[Jf[J PASSING SW
1-5. HEADLIGHT BEAM DOES NOT CHANGE
• DOES THE LEVER OF THE DIMMER•PASSING SW
OPERATE SMOOTHLY AND SECURELY?
I
I I
YES I
I NO I
I I
• DISCONNECT THE CONNECTOR OF THE DIMMER PASSING I REPAIR OR REPLACE THE DIMMER•PASSING sw J sw.
• WITH THE SWITCH AT THE LOW-BEAM POSITION, IS THERE CONTINUITY BETWEEN 13[[g] AND 16(]]U 1 ALSO, WITH IT AT THE HIGH-BEAM POSITION, IS THERE CONTINUITY BETWEEN 15(]]UAND 16 []}[) 1
I
l
I NO I
I
l REPAIR OR REPLACE THE DIMMER•PASSING SW J

8 -66 CHASSIS ELECTRICAL
•
•
•
1-6. HEADLIGHTS REMAIN ON WHEN THE LIGHTING
SW IS TURNED OFF
IS THE LIGHTING RELAY NORMAL? I
I
I I
YES I I NO J
I I
DISCONNECT THE CONNECTOR OF THE LIGHTING SW I REPLACE THE LIGHTING RELAYI
IS
THE CONTINUITY BETWEEN THE SWITCH CONNECTOR
TERMINALS 1ITI[J AND 7[[ITJ NORMAL?
I
I I
YES I
I NO I
I I I I
REPAIR A SHORT CIRCUIT BETWEEN
5
ITI]AND1~ I REPAIR OR REPLACE THE LIGHTING sw I
1-7. HEADLIGHT COME ON WITH THE LIGHTING SW
AT THE PARKING LIGHT POSITION
I REPAIR OR REPLACE THE LIGHTING sw I
..

•
•
•
•
•
CHASSIS ELECTRICAL 8-67
2-1. (WHILE THE HEADLIGHT IS ON IN LOW-BEAM}
BOTH FOG LIGHTS ARE INOPERATIVE
IS FUSE F-8 (15A) NORMAL? I
I
I I
YES I NO I
I j
IS THE FOG LIGHT RELAY NORMAL? I REPLACE THE FUSE I
I
I j
YES I NO I
I I
REMOVE THE FOG LIGHT SW REPLACE THE FOG LIGHT RELAY I
WITH THE SWITCH ON, IS THERE CONTINUITY BETWEEN
THE SW CONNECTOR TERMINALS sc:::E[J AND 4[}[]7
I
I I
YES I NO j
I J
IS THE BATTERY VOLTAGE APPLIED BETWEEN THE FOG REPAIR OR REPLACE THE FOG LIGHT sw I
LIGHT SW HARNESS SIDE CONNECTOR sill] AND THE GROUND?
I
I I
YES I NO I
I I
REPAIR A POOR CONNECTION AT THE CONNECTORS OR REPAIR A POOR CONNECTION AT THE CONNECTORS
AN OPEN CIRCUIT BETWEEN 4[}[]AND 16 [[ill OR AN OPEN CIRCUIT BETWEEN FUSE F-4 (15AI
AND 31 x-23 loR 1 Wi] AND s DD

8-68 CHASSIS ELECTRICAL
2-2. (WHILE THE HEADLIGHT IS ON IN LOW-BEAM) FOG
LIGHT
ON THE LEFT (OR RIGHT) SIDE IS INOPERATIVE
• IS THE FOG LIGHT BULB NORMAL?
I
I
YES I
I
REPAIR A POOR CONNECTION AT THE CONNECTORS OR A OPEN CIRCUIT BETWEEN 2 WU AND 6~(0R 2~AND 6[f}[]l
I
I NO I
I
l REPLACE THE BULB
NOTE: Connectors in parenthesis"()" indicates the check point of the fog light-RH.
I
•