Date:         Tue, 7 Jan 2003 12:52:33 -0500
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Re: Fridge burner indicator light bright, then dim?
Comments: To: Westyman <thewestyman@MINDSPRING.COM>
In-Reply-To:  <JBEOJOBKGBDBEAIBOCBEKELOCCAA.thewestyman@mindspring.com>
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 11:48 AM 1/7/2003, Westyman wrote:
>Mine has always come on when on 12V.
>New scenario: The light comes on full brightness when I flip on the cooling
>fan bypass switch! (this switch only bypasses the little temp sensor on the
>fins). This is with the fridge OFF totally. Ideas?

The flame detector is a very sensitive amplifier connected between the LED
panel ground reference and the fridge thermocouple.  It is designed to
light any time the thermocouple goes a few millivolts *negative* to ground
-- or conversely, any time the ground goes a few millivolts positive to the
thermocouple.  Since the reference ground is not connected directly to the
thermocouple, but rather through wires which carry current from the fridge
fan and heater (and water pump), the voltage it sees as "ground" becomes
slightly more positive any time any of these devices is drawing
current.  Depending somewhat on the condition of those grounds, the rise is
likely to be enough to cause the light to either light or become brighter.

david


--
David Beierl - Providence RI USA -- http://pws.prserv.net/synergy/Vanagon/
'84 Westy "Dutiful Passage"
'85 GL "Poor Relation"