Date:         Tue, 11 Jan 2005 19:03:14 -0500
Reply-To:     "Daniel L. Katz" <katzd54@YAHOO.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         "Daniel L. Katz" <katzd54@YAHOO.COM>
Subject:      Re: Can sender unit cause it?

no. a high temp reading implies low circuit resistance, not high.
therefore, a poor ground at the sender will cause a low temp reading.
infinite resistance (open - as in removing wire normally connected to
sender) produces gauge reading at low end; zero resistance (shorting wire
normally connected to to sender) pegs gauge at high temp end.

in any case, a pet peave of mine is all the talk about cleaning and
shining up ground connections without an appropriate diagnosis, and the
failure to understand that if the contact at the crimp is poor, it doesn't
make any difference how shiny the terminal connection, there will be a
high resistance.

if the bolts on the upper thermostat housing are corroded, the housing
will not be well bonded to the engine, and this would cause a high
resistance to ground. but the point is that it is necessary to do a proper
diagnosis, and it is a disservice to list memebers to suggest all of this
silly cleaning and polishing without any measurements to support such
action. besides, even without a meter, all you need is a single long test
lead with allegator clips to shunt around any sucpicious ground connection
to see if that cures the problem - otherwise you could clean and shine all
day and get nowhere.

my 2 cents!

dan

On Mon, 10 Jan 2005 13:55:37 -0500, Jonathan Farrugia <jfarrugi@UMICH.EDU>
wrote:

>check the resistance of the coolant sender with a multimeter and compare
>your values to the ones in the manual.  additionally check the resistance
>between the case near the sender and ground on a chassis ground point.
>resistance should be very low here, if not clean up or redo ground
>connections to make it so.
>
>the problem could be with the temp gauge circuitry in the instrument
>cluster.  they go bad, i replaced mine about a year ago and did a bit of a
>right up for the archives.  additionally mark drillock has written about
>this at length.
>
>http://gerry.vanagon.com/cgi-bin/wa.exe?
A2=ind0407A&L=vanagon&P=R13806&m=250342
>
>jonathan
>
>On Mon, 10 Jan 2005, Zoltan wrote:
>
>> I have the gauge high still.  New radiator, new engine, flushed system,
>etc.  But I still have the old sender unit and gauge.  Can any of these
>be wrong and malfunction?
>> Zoltan
>>
>>
>>