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Grady Clay Grady Clay is offline
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Join Date: Dec 2003
Location: Arapahoe County, Colorado, USA
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Conveniently I happen to have this in front of me.
The Porsche Workshop Manual says:

“How to read current flow diagrams.

“In previous wiring diagrams electrical components were
shown in the approximate position as you would find
them in the car. However, to show the electrical
connections between each component in the diagram
became more and more difficult as the number of
components increased. The result was that it was
hard to trace electrical circuits.

“To make wiring diagrams easier, we revised them
completely. The result of extensive studies is a new
diagram called ‘current flow diagram’.

“Current flow diagrams are laid out by placing circuits
of related components one next to the other. The
base of each circuit always starts with ground. The
location of components on the diagram is no longer
related to where the components would be in the car.
The layout of the circuits, however, is such that each
can be followed much easier to help troubleshooting
of electrical faults.

“Looking at a current flow diagram you will find a yellow
base line. The numbers in the yellow base line
characterize the current tracks in the diagram and
are to locate each component that is listed in the legend.

“The colored lines in the diagram represent the wires in
the car, the colors correspond with the actual colors of
the wires. The small numbers in the wiring runs indicate
the wiring gauge in mm². The thin black lines are not
actual wires but internal connections, such as ground
connections in a lamp housing. The base line for ground
is the thin black line directly on top of the yellow base line.

“Interrupted wires or connections end in a yellow square.
Continuation of this interrupted circuit can be found in
the current track using the numbers in the square.

“Each component in the diagrams identified with a letter,
sometimes with a letter and a number. Component
definition can be found in the legend.

“Most connectors or terminals are numbered. These
numbers correspond with the numbers that are right
next to most connectors on electrical components,
such as switches and relays. This numbering system
is used on most European cars. Listed below are the
most commonly used terminals and their location.”
(This is dated 1974.)

© Dr. Ing. h.c. F. Porsche A.G.

Here is a page of common electrical symbols from the diagrams.

© Dr. Ing. h.c. F. Porsche A.G.

The legends are reasonably clear where components and
connections are. It would be useful to have photo
documentation of the actual locations and reference
connections to the various wiring harnesses.

Old 10-17-2005, 12:51 PM
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