Date:         Mon, 19 Sep 2005 08:56:42 -0700
Reply-To:     Michael Elliott <j.michael.elliott@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Michael Elliott <j.michael.elliott@GMAIL.COM>
Subject:      Re: voltage in water tank?
Comments: To: Robert Harris <rdh24@CORNELL.EDU>
In-Reply-To:  <5.2.1.1.2.20050919111213.03228fc8@postoffice9.mail.cornell.edu>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

I've not seen a writeup about how the water tank level sensing systems
work (there were two types, I think). I don't know if  they have exposed
+12vdc points in the water. Fresh water is a darn good insulator. But
the more dissolved solids, such as minerals i.e., hard water,  in the
water, the greater the conductivity. The combination of a very high
impedance voltmeter (such as a good digital voltmeter) and hard water
might very well result in enough current flow to register on the meter.

--

Mike "Rocket J Squirrel" Elliott
71 Type 2: the Wonderbus
84 Westfalia: Mellow Yellow ("The Electrical Banana")
KG6RCR



On 9/19/2005 8:20 AM Robert Harris wrote:

> hi y'all,
> Yesterday I was trying to diagnose a dead sink water pump, and in the
> process happened to discover that the water in my Westy holding tank
> always
> has a voltage of +0.3 volts, even when all systems are
> off.  Ummmmm!!!!!????  Is this normal?  I am wondering if the water level
> LED "meter" thingy is malfunctioning.  No schematic handy.  The meter
> does
> work fine and turning it on makes the voltage of the water go up to
> +1.5volts.  This is an '84 Westy.
>
> In the interest of science if anybody could stick a multimeter probe in
> their water tank and see if there's voltage when everything's off, I'd be
> grateful.
>
> thanks,
> Robert H
> Ithaca, NY
> 84 Westy "Busaru"
>