>
> As far as I can tell it's not actually a cooling issue but an
> electrical or sensor issue but I may be wrong.
> Any idea what causes this?

Coolant level sensor? Relay '43'? Maybe even the wiring between the two, but
wire seldom goes bad. As I recall, if the temperature is OK the system only
pegs the needle and flashes the light when a) the coolant is low, or b) when
the relay/wiring/sensor for the coolant level system is failing. If you
suspect the sensor, plug a 2K ohm resistor into the connector in place of
the level sensor at the coolant bottle (everyone has a 2K ohm resistor lying
around, right?). If it still acts up it's either the '43' relay or the
wiring between.

--
John Bange
'90 Vanagon - "Geldsauger"