Schematics
Schematic Diagrams
Schematics 1988
928s4
Pin and function conventions
DIN 72 552
CEB connector numbering
Wiring Diagram
Wiring Loom 1989- S4 GT
GTS
Porsche 928
Electrics WDP Only
Layout of T18 (14p at
side wall) connector
Layout of 12pin diagnostic
connector
Electrical
Engine related
Fault
codes The
Diagnostic tool and fault codes
Fault code 1214
Start
problems and power connections
Powering Fuel pump, LH and EZK Ignition/Switch/Starter
problems
Ignition switch assembly
Engine
not turning over Sometimes
it won't start: starter relay S4
control unit coding (GAS octane)
Cooling Fan
Fan Power stage repair
Fan Power stage repair service
Fan Power stage repaired
Fan controller module
repair
Fan control unit
troubleshooting
Cooling Fan system Sensors
Cooling Fan funny business
Cooling fan circuit
explained
Testing the Fan power and
fan operation
Fan motor
reconditioning
Fan motor internals and repair
Fan motor replacement
Fan running problems
Fan shroud and fan motors
Fan motor fuse panel
meltdown
Intake cool down sensor
Flap and fan engine cooling design
Battery and Alternator
Battery Choices
Battery Specs and Dimensions
(Varta, Berga, Exide)
Battery Ground Strap
More info on battery tech
Car
Battery FAQ
Battery terminal
connections
Battery drain
Battery drain issues
Batteries testing current draw checking proc
Battery drain probing and
short circuit tester
Battery maintenance and charging
Battery maintenance
Battery Charging
Battery Charging FAQ
Ground straps
Ground straps cleaning
Ground points for ECU's 
Alternator Pictures and
info 115A version
Alternator wiring
Alternator cooling
Alternator and Resistor
types in pre-S4
Alternator
woes: (lack of) charging
Alternator charging failure

Alternators and charging
Alternator or battery dead
Alternator Rebuild 115A
Alternator Rebuild
Alternator Regulator repair
Alternator (Lichtmaschine)
Überholung 
Alternator test
Alternator testing
Alternator models and specs
Alternator Brushes and parts
Alternator Diodes testing
Alternator
belt almost broken
Alternator Parts Bosch
Voltage adjustable Regulator
Voltage fluctuations
Voltage low
Voltage problems and over-voltage
damage
Starter
Starter motor assembly and
mounting
Starter does not work
Starter solenoid
Jump starting a 928
Engine slowly starting
Starter motor assembly and mounting location
Cable loom
Engine bay cable loom GTS
Layout of T18 connector
Wiring loom interconnect
plug
Various pictures wiring
loom 1989-1991 S4
Central Electrics Board (CEB)
Blower fuse fried on CEB
Differences CEB
CEB complete layout
Fuse assembly
CEB maintenance and repair
CEB panels overview part
numbers
Windshield drain
Electrical Maintenance Job
Annual Electrical Maintenance
*AMP connectors and repair
|
Control Units
Control Units
Annotated view and parts **
Control Units locating
Cruise Control unit repair
Cruise Control connector pinning
Cruise Control
understanding the VDO Amp
Cruise Control unit actuator
Resetting the Brake Warning light
Diagnosing central warning light
Repairing Central Warning Unit
Central Warning Light explained
Central Warning System Repair
Central Warning ECU Repair
Center console AC and lock control assembly
Diagnosing the Tail Light warning
light
Bulb controller problems
Bulb check controller and LED bulbs
Bulb (lamp) check unit bypass
Bulb (lamp) control unit
modification
Bulb control unit differences
Jumpers / Bridges for the anti theft
device
Alarm controller in a S4/GT/GTS

Alarm controller Hella (up to 1990)
Alarm controller Megamos
Alarm anti theft relay in center
console
Alarm units overview
Keyless entry installation
Keyless entry installation MT400
Waeco

Fit Sachs remote control and alarm

HVAC controller and console repair
Seat controller
Central locking controllers
Power window controller inside
Power window controller info and
repair
Relays and Fuses
Relays detailed info
**
Fuse and Relay changes / year Alan Moore
Fan motor fuse panel meltdown
Relays and Fuses 1992-1995 GTS
Relays and
Fuses 1992 GTS
Relay-Chart_REV5212012-v1-for-1989-S4
Relay-Chart_REV20120523-v2-for-1994-GTS
Chine relay, special units
Chine relay, installing the lights-on warning
unit
Alarm anti theft relay in center
console
AC electrics
Clutch Power Relay problems
AC electrics Clutch
Power Relay
pinning and layout
What is an X - Relay ?
Relay X clacks
Headlight Relay
Water leaking on the Relay panel
Fuel Pump Relay bypass
The FCU Relay (XIX)
ABS Pump Relays
PSD pump Relay
Seat heating Relay
Daylight Running Lights Relay
Labels on Relays
How to remove a stubborn Relay
Heat effect on Relays
Accessories
Where to take 12V accessories power
from
Bosch docs
Bosch
sensor information
Bosch knock tech
Bosch Fuel
Injection Systems
Bosch_ABS_2S
Bosch
Technical Instruction-Jetronic
Bosch
Technical Instruction L-Jetronic
Airbag
Airbag crash sensors
Ignition switch
Ignition switch removal
Ignition switch assembly
Ignition switch problems
Misc
Wiring Diag help - How to Read the
Schematic
Door switch fix

How to build
a Lambda and MAF meter
Early car backup lights
9268 tester manual rewritten
Tester
Instructions ver 7
GTS won't start, starter lockout
Bulbs and
lights
GTS bulbs overview
All the 928
bulbs in overview
Bulb
replacement list
Car Bulbs and
specs generic overview
LED changeover
Third brake light
Fog lights
LED conversion (for daylight driving lights)
Converting Interior Lighting to LEDs by Ed Scherer
Interior lights
Interior lights stay on
Hood light pre 1990
License plate
illumination
No reverse
light when front lights are off
|