battery ISUZU TF SERIES 2004 Owner's Guide

8A-4 ELECTRICAL-BODY AND CHASSIS
GENERAL INFORMATION
The body and chassis electrical system operates on a twelve volt power supply with negative ground polarity.
The main harness consists of the engine harness, the instrument harness, the body harness, and the chassis
harness.
The harnesses use a split corrugated tube to protect the wires from the elements.
Wire size is determined by current flow, circuit length, and voltage drop.
All wires have color-coded insulation.
Wire color-codes are shown in the circuit diagrams.
This makes it easier to trace circuits and to make the proper connections.
Each circuit consists of the following:
1. Power source - The battery and the alternator
2. Wires - To carry electrical current through the circuit
3. Fuses - To protect the circuit against current overload
4. Relays - To protect voltage drop between the battery and the circuit parts and to protect the switch points against
burning
5. Switches - To open and close the circuit
6. Load - Any device, such as a light or motor, which converts the electrical current into useful work
7. Ground - To allow the current to flow back to the power source

ELECTRICAL-BODY AND CHASSIS 8A-5
NOTES FOR WORKING ON ELECTRICAL ITEMS
Battery

BATTERY CABLE
Disconnecting the Battery Cable
1. All switches should be "OFF" position.
2. Disconnect the battery ground cable.
3. Disconnect the battery positive cable.
CAUTION:
It is important that the battery ground cable be
disconnected first.
Disconnecting the battery positive cable first can result in
a short circuit.














Connecting the Battery Cable
Follow the disconnecting procedure in the reverse order to
connect the battery cables.
CAUTION:
Clean the battery terminal and apply light coat of grease to
prevent terminal corrosion.




CONNECTOR HANDLING
Disconnecting the Connectors
Some connectors have a tang lock to hold the connectors
together during vehicle operation.
Some tang locks are released by pulling them towards you
1.
Other tang locks are released by pressing them forward
2.
Determine which type of tang lock is on the connector being
handled.



Firmly grasp both sides (male and female) of the connector.
Release the tang lock and carefully pull the two halves of the
connector apart.
Never pull on the wires to separate the connectors.
This will result in wire breakage.

ELECTRICAL-BODY AND CHASSIS 8A-11
SYMBOLS AND ABBREVIATIONS
SYMBOLS
Symbol Meaning of Symbol Symbol Meaning of Symbol


Fuse
Bulb



Fusible link
Double filament bulb



Fusible link wire
Motor


Switch
Variable resistor Rheostat


Switch
Coil (inductor), solenoid,
magnetic valve


Switch (Normal close type)





Contact wiring
Relay


Battery




Diode
Connector


Electronic Parts
Light emitting diode



Resistor
Reed switch


Speaker
Condenser



Buzzer
Horn


Circuit breaker
Vacuum switching valve

8A-16 ELECTRICAL-BODY AND CHASSIS


RELAY
Battery and load location may require that a switch be placed
some distance from either component.
This means a longer wire and a higher voltage drop
1. The
installation of a relay between the battery and the load reduces
the voltage drop
2.
Because the switch controls the relay, amperage through the
switch can be reduced.


Relay Specifications and Configurations
Name/
Color Rated
voltage/ Coil
resistance Internal circuit Name/
color Rated
Voltage/Coil
resistance Internal circuit
1T
(MICRO
ISO)
/Black 12V
Approx. 92
Minimum
operating
voltage: 7V at
20C (77F)

1M (MINI
ISO)
/Black 12V Approx.
94 Minimum
operating
voltage: 7V at
20C (77F)

1M
(MICRO
ISO)
/Black 12V
Approx. 132-3
 Minimum
operating
voltage: 7V at
20C (77F)

1M
(power)/
Black 12V Approx.
94 Minimum
operating
voltage: 7V at
20C (77F)

* Relay contact shown in the wiring diagram indicates condition before actuation.

ELECTRICAL-BODY AND CHASSIS 8A-19
Battery-1

BATTERY
Inspection
1. Check the battery terminals 1 for corrosion.
2. Check the battery cables
2 for looseness.
3. Check the battery case
3 for cracks and other damage.
4. Check the battery electrolyte level.

Battery-2

Battery Replacement
1. Disconnect the battery ground cable 1.
2. Disconnect the battery positive cable
2.
3. Remove the battery clamp
3.
4. Remove the battery
Caution:
It is important that the battery ground cable be removed
first.
Removing the battery positive cable first can result in a
short circuit.


Jump Starting the Engine with a Booster Battery
The following description assumes that you are using a booster
battery mounted on a second vehicle.
The listed steps (with some minor modifications) are also
applicable if you are using a naked booster battery or special
battery charging equipment.

8A-20 ELECTRICAL-BODY AND CHASSIS

Caution:
Never push or tow the vehicle in an attempt to start it.
Extensive damage to the emission system and other
vehicle parts will result.
(Only catalytic converter vehicle)
Treat both the discharged battery and the booster battery
with great care when using jumper cables.
Carefully follow the procedure outlined below.
Always be aware of the dangers of sparking.
Failure to follow the following procedure can result in:
a. Serious personal injury, specially to your eyes.
b. Extensive property damage from a battery explosion,
battery acid discharge, or electrical file.
c. Extensive damage to the electronic components o
f
both vehicles.
Do not use a 24 volt booster battery.
Serious damage to the vehicle's electrical system and
electronic components will result.

Jump Starting Procedure
1. Set the parking brake on both vehicles.
2. If one or both vehicles is equipped with a manual
transmission, place the gear shift in the "NEUTRAL"
position.
3. Turn off the ignition on both vehicles.
4. Turn off all vehicle lights and accessories.
5 Be sure that the two vehicles are not touching.

Attach the end of one jumper cable to the booster battery
positive terminal.
6
Attach the other end of the same cable to the discharged
battery positive terminal.
7. Once again, check that the booster battery has a 12 vol
t
rating.
8.
Attach one end of the remaining booster cable to the
booster battery negative terminal.
9.
Attach the other end of the booster cable to a solid ground
(such as the air conditioner compressor mounting bracke
t
or the alternator mounting bracket) in the engine room o
f
the vehicle with the discharged battery.
Be sure that the ground connection is at least 500 mm (20
in) from the discharged battery.

ELECTRICAL-BODY AND CHASSIS 8A-21

Caution:
Do not attach the booster cable to the discharged battery
negative terminal.

11. Start the engine of the vehicle with the booster battery.
Check that all unnecessary electrical accessories are off.
12. Start the engine of the vehicle with the discharged battery.
13. Remove the jumper cables in the reverse order to which
they were attached.
Caution:
Be absolutely sure to remove the negative jumper cable
from the vehicle with the discharged battery first.

8A-88 ELECTRICAL-BODY AND CHASSIS
REMOVAL AND INSTALLATION

This illustration is based on RHD model
STARTER SWITCH
Removal
1. Steering Lock Assembly

Refer to Section 3B" STEERING COLUMN" for steering
lock assembly removal steps.
2. Starter Switch




Installation
Follow the removal procedure in the reverse order to install the
starter switch.


INSPECTION AND REPAIR


STARTER SWITCH
Switch Connections
Terminal No.

Starter
switch key
position B-62
2
(B2)B-62
4
(ACC)B-62
1
(IG2) B-63
1
(ST) B-63
3
(B1)B-62
3
(IG1)
Removed

OFF
ACC Inserted
ON
START
LOCK

825R300046

Starter relay
Check continuity between the relay terminals.
1 - 4............................. No continuity
(When battery voltage is applied between 2 and 3)
1 - 4............................. Continuity

8A-120 ELECTRICAL-BODY AND CHASSIS
TROUBLE SHOOTING
HEADLIGHT
1. Both the headlights (high and low beam) do not light

Checkpoint Trouble Cause Countermeasure


Repair the wiring

Poor ground point contact
NG

Repair open circuit or
connector contact


Repair open circuit


Repair or replace the
combination switch


Voltage between 1
B-60 -
ground


Open circuit between lighting
relay and lighting switch

Open circuit between battery
positive terminal and lighting
relay

Combination switch continuity

Poor switch contact or sw
faulty

Voltage between
5
X-12 - ground and
2
X-12 - ground


Reinstall or replace the
lighting relay

Lighting relay

Poor relay contact or relay
faulty

NG NG NG NG OK
OK
OK OK

Ground point contact (C-36)


Repair open circuit
Wiring continuity between

B-60 - C-36


Open circuit
NG OK

ELECTRICAL-BODY AND CHASSIS 8A-123
7. Passing light does not function when dimmer switch is operated

Checkpoint Trouble Cause Countermeasure


Repair or replace the dimmer
switch

Dimmer switch

Poor switch point contact
NG

Repair open circuit between
4
X-12 - 3 B-60

Voltage between
3
B-60 - ground (Should
be battery voltage present)


Open circuit
NG OK



8. Headlight beam does not change when dimmer switch is operated

Repair or replace the dimmer
switchDimmer switchLoose beam lever or foreign
material in switch NG