Not to mysterious. There are fuel guages used in airplanes that measure
the resistances in fuel as the volume changes, and translates this
measurement into units on the guage in the cockpit. Why not measure the
density of the antifreeze in relation to the water to operate a warning
light?? Less water, more antifreeze, more resistance, the light comes on
and blinks. If the tank goes dry, no water, no antifreeze, infinite
resistance (nothing to conduct a current between the posts so the
resistance is so great current cannot flow) the light  blinks. Basic
principle.

Regards,

John Rodgers
88 GL Driver

Jeff Oxroad wrote:

> Rodgers, fascinating stuff that news about the sensor sampling the
> density of the coolant mixture. I had no idea it was that
> sophisticated. That's James
>
>Bond stuff, "Excuse me Miss Moneypenny, but this blinking light tells me this
>Martini is a bit light on Gin." Thanks for that info. (on the coolant sensor).
>
>