I believe this can happen because your coolant has too much proportion
of syrup and not enough water. The colored syrup has less conductivity
than water, which means it passes less electricity through the
sensor's electrodes. At some threshold of concentrate, your gauge sees
no electricity passing through the coolant and assumes your coolant is
low.

There is actually a measuring device for the concentrate of coolant, I
think it is called a hydrometer. The instruction book for Vanagon says
mix your coolant outside and pour it in for this very reason.

As an oddity, while this is happening turn on your headlights and you
may see the flashing stop. Probably due to slightly lower voltage on
the electrodes.

-- Gnarlie

On Wed, Apr 30, 2014 at 8:11 PM, Mister Tom <TomsGroups@salicos.com> wrote:
> The "Overtemp" LED blinks after I start the van, but doesn't stop.
>
> Not always, but more frequently now, it seems.
>
> Sometimes shutting off the ignition and re-starting will reset it.
>
>
>
> The fact that it does not stop when I start the van makes me think it is the
> test circuit not shutting off.
>
> The coolant level is fine and this occurs before the engine has had time to
> warm up, let alone overtemp.
>
>
>
> Is that the "big" electrolytic  capacitor? Does it charge up to say the test
> time period is done, to stop the test flashing?
>
>
>
> I have a Bentley, but don't see details of this circuit.
>
>
>
> I can shotgun the cap if it's what I think it is, or certainly welcome to
> other tips.
>
>
>
> TIA
>
>
>
> Tom Salicos
>
> '87 Syncro Westy EG-33.