Land Rover Defender Electrical Library 3rd Edition Nas Rover Manual

Electrical Library 

CONTENTS
DEFENDER 90 NASREV: 9/97INTRODUCTION.................................................................................1
FUSE DETAILS....................................................................................1
CIRCUIT OPERATION
ENGINE IMMOBILIZATION (CODING) ................................1
STARTING AND CHARGING  ...............................................2
GENERIC ENGINE MANAGEMENT SYSTEM (GEMS)   .....4
SEAT BELT WARNING  .......................................................12...

INTRODUCTION
DEFENDER 90 NAS1This Reference Library is designed to be used in conjunction with the Circuit Diagrams
as an aid to the diagnosis of electrical faults. When diagnosing faults using TestBook, the
circuits and library will prove a useful source of additional information, enabling you to
study the operation of the circuit, isolate the suspect sub-circuit and quickly locate
connectors, without unnecessary removal of trim. The library has 2 sections; Circuit
Operation and Connector Detail.
1....

INTRODUCTION
2DEFENDER 90 NAS 
 
 
· Photograph - Shows the location of the subject connector. In most cases, the
photograph will indicate the amount of trim removal necessary to reveal the
connector.
 
· Face View - An outline of the connector housing, drawn from the front, showing pin
numbers (if applicable).
 
· Pin-out Table - A three column table, detailing the color and position of each wire
in the connector:
Cav - The connector pin (cavity) number.
Color - The color of wire populating the...

FUSE DETAILS
DEFENDER 90 NASREV: 9/971INTRODUCTION
The following tables give details of power supply through the engine and passenger
compartment fuse boxes.
Note:Some fuse numbers may be followed by a letter, either an ‘E’ or a ‘P’. ‘E’ denotes
a fuse located in the engine compartment fuse box, and ‘P’ a fuse located in the
passenger compartment fuse box.
Engine Compartment Fuse BoxLinkRatingFunction1100 AmpLink 3, Link 4, Link 5, Link 6, Fuse 1 (E), Fuse 2 (E), &Fuse 3 (E).260 AmpFuse 13 (P), Fuse 14...

FUSE DETAILS
2DEFENDER 90 NASREV: 9/97Passenger Compartment Fuse BoxFuseRatingFunction115 AmpInstrument pack, Multi-function ECU, Headlamp relay,Interior lamp - rear, & Warning light check unit.210 AmpRadio cassette player.35 AmpDiagnostic socket.415 AmpBlower motor - front.57.5 AmpRadio cassette player.615 AmpRadio cassette player.77.5 AmpHeadlamp - RH.87.5 AmpHeadlamp - LH.97.5 AmpHeadlamp - RH.107.5 AmpHeadlamp - LH.115 AmpIn-line resistor, Front side lamp - LH, Front siderepeater - LH, Trailer...

CIRCUIT OPERATION
DEFENDER 90 NASREV: 9/971ENGINE IMMOBILIZATION (CODING) 
DESCRIPTION  
The vehicle engine immobilization (coding) is not detectable to the customer under
normal operating circumstances.  If the code of the engine immobilization unit does not
match the code of the ECM, when power is supplied to both units, the engine will be
immobilized.  In practice this should only happen if the ECM or engine immobilization
unit are renewed without reprogramming the ECM using TestBook.  
OPERATION...

CIRCUIT OPERATION
2DEFENDER 90 NASSTARTING AND CHARGING  
CHARGING - DESCRIPTION  
The charging system consists of a generator containing a rectifier pack and regulator to
maintain a constant direct current (d.c.) voltage in the system.  The generator is belt
driven from the crankshaft and cooled by a fan mounted behind the pulley.  The generator
has a fixed coil wound stator in which a field coil rotor rotates. Slip rings conduct current
to and from the field coils via 2 carbon brushes.  The regulator...

CIRCUIT OPERATION
DEFENDER 90 NAS3STARTING - OPERATION  
When the ignition switch is in position II, power flows across the switch to fuse 20 of the
passenger compartment fuse box (C581-13) on the white wire.  Fuse 20 (C581-20) is
connected to the fuel pump relay winding in the ECM relay module (C154-2) by the
white/green wire.  The fuel pump relay winding (C154-1) is grounded through the  ECM
(C634-24) on the blue/purple wire.  The ECM grounds the fuel pump relay winding for a
short time when the...

CIRCUIT OPERATION
4DEFENDER 90 NASGENERIC ENGINE MANAGEMENT SYSTEM (GEMS)   
DESCRIPTION  
GEMS is the engine management system utilized by the vehicle to control both electronic
ignition and fuel injection systems. It is able to alter ignition and fuelling settings to
ensure that the engine is operating at its optimum performance for the prevailing
conditions.  The ECM receives signals from sensors located around the engine and uses
the data to control the fuel quantity, fuel injection timing and...