Page 26 of 284
ELECTRICAL SYSTEM PARTS LOCATION - Fusible Link and Fuse
FUSIBLE LINK AND FUSE
--
Items
Dedicated fuse (for air conditioner circuit)
Dedicated fuse (for headlight circuit)
Main fusible link
Multipurpose fuse
Sub fusible link
NOTE Symbol
B
‘I
E
A
C
D
For detailed information concerning the fusible links and
fuses, refer to the section regarding CENTRALIZED JUNC-
TION (P.8-69, 70.)
16W722
-Evaoorator 1
/ STBI levision
Page 27 of 284
ELECTRICAL SYSTEM PARTS LOCATION -Grounding 8-7
GROUNDING
I
Headlight
washer relay,
h !Ja -/
_ .-----
/ 1 STB Revision
Page 30 of 284
8-10 INSPECTION OF HARNESS CONNECTOR - Inspection of Harness Connector
Housing lance
-5
1 16R1321
’ Needle
16Ffi322
Housing lance
16R1323 (2) Insert harness of terminal to be rectified deep into connector
from harness side and hold it there.
(3) Insert tip of screwdriver [1.4 mm (.06 in.) width] into connector
in a manner as shown in the figure, raise housing lance slightly
with it and pull out harness.
NOTE
Tool No. 753787-l supplied by AMP can be used instead
of screwdriver.
(4) Insert needle through a hole provided on terminal and raise
contact point of male terminal.
ROUND WATERPROOF CONNECTOR (1) Remove waterproof cap by using a screwdriver.
(2) Insert tip of screwdriver [1.4 mm (.06 in.) or 2.0 mm (.08 in.)
width] into connector in a manner as shown in the figure, raise
housing lance slightly with it and pull out harness.
(3) Insert screwdriver through a hole provided on terminal and
raise contact point of male terminal.
Page 31 of 284
INSPECTION OF HARNESS CONNECTOR - Inspection of Harness Connector 8-71
RECTANGULAR WATERPROOF CONNECTOR
(1) Disengage front holder by using a screwdriver and remove it.
(2) Insert tip of screwdriver [*0.8 mm (03 in.) width] into connec-
tor in a manner as shown in the figure, push it lightly to raise
housing lancer and pull out harness.
*If right size screwdriver is not available, convert a conven-
tional driver to suit the size.
Housing lance
16R13 26
16R1329
L 16R1326)
(2)
Terminal lance
16Rl330
1 STB Revision (3) Press contact point of male terminal down by holding a screw-
driver [1.4 mm (.06 in.) width] in a manner as shown in the
figure.
INJECTOR CONNECTOR
(1) Remove waterproof cap.
Insert tip of screwdriver [1.4
in a manner as shown in the
pull out harness. mm (06 in.) width] into connector
figure, press in terminal lance and
Page 34 of 284

8-14 WIRING HARNESS - Troubleshooting
1680222
Changeover knob 1680224
1680225 1
1680226
INSPECTION
1. Visual and aural checks
Check relay operation, blower motor rotation, light illumina-
tion, etc. visually or aurally. The flow of current is invisible but
can be checked by the operation of the parts.
I
2. Simple checks
For example, if a headlight does not come on and a faulty fuse
or poor grounding is suspected, replace the fuse with a new
one or ground the light to the body by a jumper wire to deter-
mine which part is responsible for the problem.
3. Checking with instruments
Use an appropriate instrument in an adequate range and read
the indication correctly. You must have sufficient knowledge
and experience to handle instruments correctly.
INSPECTION INSTRUMENTS
In inspection, make use of the following instruments.
1. Test lamps
A test lamp consists of a 12 V bulb and lead wires. It is used
to check voltages or shortcircuits.
2. Self-power test lamp
A self-power test lamp consists of a bulb, battery and lead
wires connected in series. It is used to check continuity or
grounding.
,.!‘?i,
,, 6
,‘.’
1 STB Revision
Page 36 of 284

8-16 WIRING HARNESS - Troubleshooting
OFF
1st stage
2nd stage
3rd stage
1
--_
4th stage
1660230
16W896
Cover
Coil
Iron
piece Spring
Iron
core
Contact
1660231
I
l-
Battery:
I
-
d
T Relav
T I
I 1660232 1
Normal ooen (NO) tvoe
Deenergized state Energized state
I
1
2
ED
3
4
1 2
BP
3
4
1 YZZZw;6B0233 CurreZ! not flow
2. SWITCH CONNECTION
This figure illustrates a complex switch. The switch plates
indicated by solid lines move in the direction of the arrow
when
operated. The continuity between terminals at each po-
sition is as indicated in the table below.
NOTE
M denotes continuity between terminals.
CHECKING RELAYS
1. When current flows through the coil of a relay, its core is
magnetized to attract the iron piece, closing (ON) the contact
at the tip of the iron piece. When the coil current is turned off,
the iron piece is made to return to its original position by a
spring, opening the contact (OFF).
2. By using a relay, a heavy current can be turned on and off
by a switch of small capacity. For example, in the circuit
shown here, when the switch is turned on (closed), current
flows to the coil of the relay. Then, its contact is turned on
(closed) and the light comes on. The current flowing at this
time to the switch is the relay coil current only and is very
small.
3. The relays may be classified into the normal open type and the
normal close type by their contact construction.
NOTE
The deenergized state means that no kurrent is flowing
through the coil and the energized state means that current is
flowing through the coil.
J . . . I 1 STB Revmon
Page 37 of 284

Normal close INC) type
Deenergized state
Energized state
I
WIRING HARNESS - Troubleshooting 8-17
When a normal close type relay as illustrated here is checked,
there should be continuity between terminals (1) and (2) and
between terminals 3 and 4 when the relay is deenergized,
and the continuity should be lost between terminals 3 and 4
when the battery voltage is applied to the terminals 1 and 2. A
relay can be checked in this manner and it cannot be deter-
mine if a relay is okay or faulty by checking its state only when
it is deenergized (or energized).
Current -flows Current does not flow
1680234
=
1680235
State of fuse blown due to overcurrent
1660237
I
State of fuse blown due to thermal fatigue
CHECKING FUSES
A blade type fuse has test taps provided to allow checking of
the fuse itself without removing it from the fuse block. The
fuse is okay if the test light comes on when its one lead is
connected to the test taps (one at a time) and the other lead is
grounded.
(Change the ignition switch position adequately so that the
fuse circuit beomes live.)
CAUTIONS IN EVENT OF BLOWN FUSE
When a fuse is blown, there are two probable causes as follows
: One is that it is blown due to flow of current exceeding its rating.
The other is that it is blown due to repeated on/off current flowing
through it. Which of the two causes is responsible can be easily
determined by visual check as described below.
(1) Fuse blown due to current exceeding rating
The illustration shows the state of a fuse blown due to this
cause. In this case, do not replace the fuse with a new one
hastily since a current heavy enough to blow the fuse has
flowed through it. First, check the circuit for shorting and
check for abnormal electric parts. Only after the correction of
such shorting or parts, fuse of the same capacity should be
used as a replacement. Never use a fuse of lager capacity than
the one that has blown. If such a fuse is used, electric parts or
wirings could be damaged before the fuse blows in the event
an overcurrent occurs again.
(2) Fuse blown due to repeated current on/off
The illustration shows the state of a fuse blown due to re-
peated current on/off. Normally, this type of problem occurs
after fairly long period of use and hence is less frequent than
the above type. In this case, you may simply replace with a
new fuse of the same capacity.
Page 38 of 284

WIRING HARNESS - Troubleshooting
1660236
Power
supply
h
Fuse
ON
/----
/
/
Motor
1660239
CHECKING CABLES AND WIRES
1. Check connections for looseness, rust and stains.
2. Check terminals and wires for corrosion by battery electrolyte,
$tc.
3. Check terminals and wires for open circuit or impending open
circuit.
4. Check wire insulation and coating for damage, cracks and de-
grading.
5. Check conductive parts of terminals for contact with other
metallic parts (vehicle body and other parts).
6. Check grounding parts to verify that there is complete conti-
nuity between attaching bolt(s) and vehicle body.
7. Check for incorrect wiring.
8. Check that wirings are so clamped as to ‘prevent contact with
sharp corners of the vehicle body, etc. or hot parts (exhaust
manifold, pipe, etc.).
9. Check that wirings are clamped firmly to secure enough clear-
ance from the fan pulley, fan belt and other rotating or moving
parts.
10. Check that the wirings between the fixed parts such as the
vehicle body and the vibrating parts such as the engine are
made with adequate allowance for vibrations.
HANDLING ON-VEHICLE BAlTERY
When checking or servicing does not require power from the on-
vehicle battery, be sure to disconnect the cable from the battery
(-)terminal. This is to prevent problems that could be caused by
shorting of the circuit. Disconnect the (-) terminal first and recon-
nect it last.
TROUBLESHOOTING
A circuit consists of the power supply, switch, relay, load, ground,
etc. There are various methods to check a circuit including an
overall check, voltage check, shortcircuit check and continuity
check. Each of these methods is briefly described in the following.
1. Voltage check
(1) Ground one lead wire of the test light. If a voltmeter is
used instead of the test light, ground the grounding
side lead wire.
(2) Connect the other lead wire of the test light to the
power side terminal of the connector 0. The test light
should come on or the voltmeter should indicate a
voltage.
(3) Then, connect the test light or voltmeter to the
connector (3,. The test light should not come on, or the
voltmeter should indicate no voltage. When the switch
is turned on in this state, the test light should come on,
or the voltmeter should indicate a voltage, with the
motor starting to run.
(4) The circuit illustrated here is normal but if there is any
problem such as the motor failing to run, check
voltages beginning at the connector nearest to the
motor unit the faulty part is identified. 1 ST6 Revision