I found a repair...

http://www.brick-yard.co.uk/forum/westy-water-tank-level-sensor-
repair_topic42742.html

hey, it is a reed switch based gizmo, I swear I guessed that before
finding repair article.. really :0

alistair

On 6-Aug-10, at 7:14 PM, Ed Wiebe wrote:

For about 2 years now we have been travelling/camping not knowing how
much water we still have on board because the sensor has a burnt out
part.  If you go here: http://picasaweb.google.ca/ewieber/
WestyDomesticWaterTankLevelSensor# you can see the broken part.  What
is it and is it easy to find a working replacement.  It shouldn't be
hard to solder a new part in.
Another option: Does anyone have a working unit from a parted out
Westie?  What would be a reasonable price?  This is from a 1990
Wesfalia camper.  I live on Vancouver Island in British Columbia.
By the way, can someone explain how the unit senses the water level?

Ed Wiebe