Allan,

Don't have my Bentley around but the
head sensor dose not ring a bell with
me! But you could be right, others can
verify for us. I don't recall anything
about head temps, I figured the LED was
just to catch your eye to get you to
look at a gauge. We all know that gauge
will mean nothing if you don't look!

Shawn

> -----Original Message-----
> From: Allan Streib
> [mailto:streib@cs.indiana.edu]
> Sent: Sunday, December 02, 2007 9:39
> PM
> To: robert feller
> Cc: vanagon@GERRY.VANAGON.COM
> Subject: Re: New thermostat funky?
>
> I thought there were two senders for
> the gauge -- one in the water
> for the actual meter, the other in the
> cylinder head to light the LED
> when a overtemperature condition
> occurred.
>
> The problem with putting the
> temperature sender in the water is of
> course that if you lose your water you
> also have lost what you are
> measuring.  I guess that's what the
> blinking "low coolant" LED is for...
>
> Am I thinking of a different engine
> that had the two sensors?  If not
> would there be a way to retrofit a
> cylinder head temperature sensor?
>
> Allan
>
> On Dec 2, 2007, at 8:44 PM, robert
> feller wrote:
>
> > I respect Scott's comment but i will
> decent on this one.
> >
> > We went the 100% crazy route when we
> thought my gauge was reading
> > high (7/8)
> > and sometimes red light on warm
> days. New sensor, stat, radiator,
> > wiring
> > check, voltage stabilizer/reguator
> ect. Finally got the infered gun
> > and
> > compared locations and temps to my
> buddies 2.1L and we took exact temp
> > readings but our gauges showed
> different data. it's hard to say
> > what is
> > "dead on" with these gauges. I did
> tons of research with Bentley,
> > VDO and VW
> > tech manuals trying to figure out
> all Ohm readings for a given
> > temp. Lot of
> > work and poor data out there to find
> that different resources gave
> > slightly
> > different Ohm readings for arbitrary
> gauge readings. I've got the
> > sources
> > for those interested.
> >
> > Combine this to a gauge that reacts
> wide and slow due to the
> > radiator being
> > so far forward and I've never been a
> huge fan of the temp gauge on
> > these
> > things for the often OVERCOOLED
> vanagon engine.
> >
> >