Date: Thu, 3 Nov 2011 18:27:26 -0700
Reply-To: mark drillock <mdrillock@COX.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: mark drillock <mdrillock@COX.NET>
Subject: Re: D15 connector revealed
In-Reply-To: <A9355B42-5ECC-4A0F-9086-164AFF6059C8@SHAW.CA>
Content-Type: text/plain; charset=windows-1252; format=flowed
I think the magic factor may simply be TIME. The ignition coil and the
crankcase vent heater get current through that pin 100% of the time that
the vehicle is running.
That same 86+ fuse/relay panel was fitted to various other VW cars
before, during, and after it was used in Vanagons. The weak pin D15 has
a paired larger pin 23 that has the same signal. In other VWs the
factory used the stronger D23 pin for the same purpose the Vanagon uses
the weaker pin for. IMHO a mistake was make in Vanagons when they used
the weaker pin and left the stronger pin empty. I have a theory as to
how the error happened. If you look at the early 86 wiring that pin had
almost no load and only turned on a relay and the relay powered the
other things. Some frugal engineer decided the small pin was enough for
this and reserved the large pin for a future option. Then the engine
compartment wiring changed and they stopped powering the coil from the
relay and used the D15 pin to power it plus they added the heating
element. The pin specs said it could handle the load so no wiring change
was deemed needed at the dash fuse/relay end and this worked fine for 20
years before the shortcoming became apparent.
Mark
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!
> This would burn the crap out of those contacts, as Alistair's photos depict.
> How did this happen?
>
> Show me and I'll join your parade...
>
> Pz
>
> On 2011-11-03, at 3:28 PM, David Beierl wrote:
>
>> At 10:27 PM 11/2/2011, Phil Zimmerman wrote:
>>> When observing burnt positive connections on anything Vanagon related;
>>> I wonder what ground(s) were adding to the impedance that caused the heating?
>>
>> Any such ground problems, while decreasing circuit function as a whole, would lessen, not aggravate, contact burning at a different location.
>>
>> Yours,
>> David
>
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