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