Date:         Mon, 9 Sep 2002 22:04:45 -0400
Reply-To:     David Brodbeck <gull@CYBERSPACE.ORG>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Brodbeck <gull@CYBERSPACE.ORG>
Subject:      Re: Headlight upgrade questions
Comments: To: Jack <john.cook58@VERIZON.NET>
In-Reply-To:  <3D7CC935.14693.1F6185@localhost>
Content-Type: TEXT/PLAIN; charset=US-ASCII

On Mon, 9 Sep 2002, Jack wrote:

> But an even more fundamental purpose of fuses is to prevent fires,
> regardless of wire size.  Can there be a fire without drawing enough
> current to damage the wire?  You bet!  The probability of that happening
> can be reduced (but not eliminated) by reducing the fuse size to the
> minimum necessary.

If you're gong to worry about this, I have something more serious you may
want to think about.  A careful look at the wiring diagram in my Bentley
seems to indicate that, at least on my '82 Diesel, much of the wiring has
no fuse protection at all!  This includes the fuel solenoid and 'ignition'
switch circuit, and the entire instrument cluster.  They're all wired off
the battery side of the fuse panel.  I wonder if putting in a master
fusible link would be a good idea?

> Someone on this list, a month or two ago, described a situation where he
> discovered a defective wire terminal connection in his vanagon (fuse
> block?).  The crimp connection was bad (high resistance) and was heating.
> Ifirc, it was getting close to where it could have started a fire.  The
> circuit fuse had not and may not have blown until after a fire was
> initiated (and a true short developed), but by then the fire may have been
> self-sustaining.

I don't think a fuse will save you there, until something serious starts
to happen.  The high-resistance connection, even as it heats up, will
cause *lower* current than usual to be drawn.  The fuse will think
everything is peachy-keen.

             _ _
  __ _ _   _| | |  | David M. Brodbeck (N8SRE)              Ypsilanti, MI
 / _` | | | | | |  +-----------------------------------------------------
| (_| | |_| | | | @ cyberspace.org
 \__, |\__,_|_|_| "The VW camper is a brilliant invention -- it's like a
 |___/             Swiss army knife for the road... It's the stealth RV."
                                                        -- Wayne Curtis