Date: Tue, 25 Sep 2012 19:16:17 -0400
Reply-To: David Beierl <dbeierl@ATTGLOBAL.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: David Beierl <dbeierl@ATTGLOBAL.NET>
Subject: Re: Bentley Wiring Diagrams, was other stuff.
In-Reply-To: <00d001cd9b4d$b74d3590$25e7a0b0$@gmail.com>
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At 02:43 PM 9/25/2012, Stuart MacMillan wrote:
>There is no comparison between these chicken scratchings and the later
>wiring diagrams, which are MUCH better. I feel I'm pretty much on my own
>after this experience.
I lived with the '83/4 diagram for fifteen years and it served me
very well, not to mention the few hundred electrical
questions/problems I've helped solve on the list for all years. The
1.9l fuse/relay panel is so comparatively simple that I'm not even
sure it would have made sense to string it out along the top of the
diagram, since that makes the diagram more complex. But given the
number of wires that dive into the later panel on one big connector
and emerge from it on a different one, it makes all the sense in the
world to do it with the 2.1l. Failing to do it would have made
things much more difficult. Otherwise there's little difference
beyond using mm^2 wire sizes on the later drawings instead of AWG,
which is an inconvenience on this side of the ocean.*
I wish I had a copy of the diagram in the owner's manual of my Fiat
128. It was the prettiest schematic I've ever seen, something to
hang on the wall. It showed every component in its physical location
on the vehicle, with a little drawing of the component - lights were
out at the corners and so forth. For that same reason** it was
practically useless in terms of understanding how a circuit
worked. Schematics are meant to show logical relationships,*** not
physical ones; and good ones read left to right and top to bottom as
much as possible. The Bentley diagrams put a huge amount of
information into a compact space and make it accessible. The people
who drew them were experts. Their checking/editing procedures
weren't up to their layout skills, and there are also at least an
example or two where two wires that looked adequately separated when
drawn merged when reduced to the Bentley page size. 97.13 track 22
is one - terminal 88c is not connected to the relay control coil just
above it on the drawing. I'm sure that was perfectly obvious on the
original, but they've merged in the print. The wiper relay was
mis-drawn on the '83/4 diagram (and the earlier ones?) and a failed
attempt made to correct it on the '85 by renumbering terminals. It's
drawn correctly on the later ones.
*I wonder about that - were the earlier vans actually built with US
wire gauges? I bet they weren't. The European sizes all seem to
work out as odd-numbered AWG. I bet they just picked the next larger
(lower-numbered) AWG to put on the diagram, and all those 18-ga wires
are really 19-ga.
** And another reason as well...Fiat shouldn't have provided a leaky
automobile and a clay-coated manual in the same package...it ended up
as a brick.
*** Which is why it would have been really nice if there had also
been better drawings than the ones on 97.8 et. seq. showing the
breakouts from the harnesses, wire runs, connector locations and so forth.
Yours,
d
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