I don't think your meter is sensitive enough for checking that sensor.
It's not an 'yes/no' sensor like an oil pressure switch. I believe the
resistance varies and a sensitive electronic circuit in the dash interacts
with it.  If it's new, it should be good. 
I almost never actually find a bad one.  
that circuit gives lots of troubles, but I personally don't think the sensor
is the weak part. 

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Gilles Turmel
Sent: Wednesday, September 19, 2007 12:48 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Testing coolant level sensor

Hi,
I just bought a new sensor. I put it in water and test the continuity
between the two probes.  Current should flow between the two probes. Yes
or no?  I don't have any current flowing.  Is the sensor good?
Best regards.
Gilles Turmel