NOVEMBER 2020
WWW.PNWR.ORG
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References
1. A. Caldwell, "Porsche Central Electrical Systems," Up-Fixin der
Porsche Vol. 11 Panorama, February 1997.
2. A. Caldwell, "Porsche Electrical Wiring Diagrams," Panorama,
August 2004.
3. Porsche 911 Carrera Workshop Manual, 1984-1989, PCNA WKD
482 020.
4. T. Charlesworth, "Understanding On-Board," Panorama, February,
2007.
system fault histories (including engine over-
revs) to help identify and locate the sources
of maintenance problems. Aftermarket
readers are now available for most of the
later models to allow owners to check the
stored fault codes as a diagnostic aid in
checking out their problems. One of the current
aftermarket manufacturers is Durametric
Diagnostic Software who advertises in
Panorama, phone 888-854-5523 and main-
tains a website at .
Durametric offers cable connectors and
software that will connect a laptop computer
to read any stored faults and/or analyze
stored exceedences of the various OBD
systems attached to the car's data bus. The
website shows two kits for Porsches– one for
the recent cars (Boxster, Carrera, Cayman)
costing $287 and a second one for earlier
cars (993, 964, 968, 928, and 944) for $347.
Repair and Modification Approaches
Whether your Porsche is an early model
or one of the newer more complex versions,
it is important to spend some time with the
correct wiring diagram and lay out a simp-
lified sketch of the before and after connections
required for diagnosing problems or adding/
upgrading electrical equipment. For owner
repairs or modification, if there is more than
one way to achieve the result, it is always
worthwhile to choose the approach that will
allow easy return to the original configuration.
Wherever possible, wires should be added or
disconnected at terminals and original wire
bundles left intact. Advantage should be
taken of extra fuse positions and connection
points supplied by the factory if they will
meet requirements. It is also important to
keep a legible diagram or notes of what was
done for future reference. It is often difficult
to remember the details of what was done (or worse yet, what a
previous owner did) several years earlier if there are no records.
With the specific wiring diagram for his model and proper care
and planning, the interested owner can work several the basic
Porsche electrical system problems. In addition, the correct
factory data can help identify those electrical areas where
specialized help is necessary.
Figure 3. Wiring Diagram Explanation Guide (Reference 3).
