Date:         Thu, 3 Nov 2011 21:10:34 -0400
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Re: D15 connector revealed
Comments: To: Phil Zimmerman <philzimm1@SHAW.CA>
In-Reply-To:  <A9355B42-5ECC-4A0F-9086-164AFF6059C8@SHAW.CA>
Content-Type: text/plain; charset="iso-8859-1"; format=flowed

At 08:57 PM 11/3/2011, Phil Zimmerman wrote:

>Conventional and simple resistive DC circuits theory says so… E=IR
>I have no argument here David.
>
>However, Ohm's law does not, with any 
>satisfaction, explain the burnt contacts Alistair et al, have experienced.
>Some sort of magic must have occurred that sent 
>those D15 contacts directly to ground!

No magic.  Same thing that happens to all the 
high-current connections on the van.  They age, 
oxidise (it's Alistair's van...) and the 
resistance goes up, which starts to develop a 
little heat there.  That increases the oxidation 
rate recursively, so you have a long runup with a 
fairly abrupt failure at the end.  Contacts with 
marginal capacity to begin with will succumb faster.

Yours,
David