Before I ordered a new sensor, I would pull the old one and check for corrosion.

Corrosion around the sensor where it screws into the engine will affect ground and can cause 
a change in gauge reading.

Simply clean it up, apply an antisieze compound, screw it back in and see what kind of 
readings you get.

--- On Thu, 23 Jan 1997 15:39:00 -0600  Lionel Tun <lionel@ark.prestel.co.uk> wrote:

>On the gauge the needle does not get beyond the 'block' on the left (20% of
>max), driving for half an hour in traffic with outside temp between 5 and
>10 degrees C. Is this long enough for the needle to get to the middle?
>There is plenty of heat from the front and rear heaters.
>
>I have ordered a new thermostat, but could it be the sensor itself that is
>at fault? Is it worth getting a new sensor?
>
>For a brief time after changing the coolant, the temperature did swing to
>the middle and back. Can I assume this was just due to an air bubble which
>has burped itself out - the radiator bleed screw lets out coolant.
>
>Secondly, and almost certainly unconnected, the red LED in the middle of
>the gauge does not flash even if you pull out the wire going into the
>expansion tank. Is this normal?
>
>Thirdly, I have also ordered an expansion tank pressure cap just to be safe
>- is this too paranoid?
>
>Lionel Tun
>84 GL, 183k miles
>lionel@ark.prestel.co.uk
>

-----------------End of Original Message-----------------

________________________________________________

    Michael Stocker <mdstockr@neo.lrun.com>
    North Canton, Ohio, USA
    LiMBO / GASS
    8:30:30 PM  1/23/97
________________________________________________