Date:         Sat, 9 Jun 2012 15:55:36 -0700
Reply-To:     Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject:      Re: WBX Digifant Ground Check. No Continuity Between Some Points.
Comments: To: David Beierl <dbeierl@ATTGLOBAL.NET>
In-Reply-To:  <4fd3b1db.88cae00a.112d.fffff950@mx.google.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

On 6/9/2012 1:28 PM, David Beierl wrote:
> I wouldn't use
> a test light around the ECU just in case some sender return is very
> delicate (not to mention hitting the wrong pin).
>
> I sure wouldn't either, on an ECU>
An interesting diagnostic thing someone may find useful in checking
grounds sometime...in whatever year of model of vanagon.
And that is to measure the current drop across a ground connection.
Take a headlight ground . Ideally the voltage drop across the consumer (
headlight ) is the same as the total voltage for the circuit ..say 12.5
volts.
and that would be the case if  the switch, wires, and grounds had zero
resistance and consumed no voltage..
if you put your volt meter on both sides of the headlight with the
circuit energized , your volt meter would read the 12.5 volts ..IF no
voltage was being used by the other points of the circuit..
but those wires and grounds do use some of the total voltage.

  so ..for a ground.........energize the circuit, put the meter on
milivolt scale ..
and read the voltage drop across the ground point, like one lead on the
body of the van, the other lead on the wire connector.
The max you want to see is 300 milivolts.  ( almost 1/3 of a volt )
Higher than that and you clean and tighten that ground connection and
test again.

on the van in question ...ground is ground.
Negative battery cable does not have to be connected, to find continuity
between any ground wire on the van  and the body of the van or the
engine if it's properly grounded.
Those sure better all be in common electrically.
As for a resistance value , my meter usually says .1 ohms for
continuity, 'usually-generally'.
plus I have to test my test equipment sometimes...just so things make
sense.
regardless of what year the van is,
regardless of where the information about that year is it might be.
lol.