Check this out:

http://buncombe.main.nc.us/~emaglott/pp023/pages/08.htm

Part of my instrument cluster overhaul.  You can tweak where the
gauge reads.  Maybe there's a procedure in Bentley?  Anyway, seems
better than changing the electronic characteristics of the
circuit.  If I tweaked, I would do some hot water testing to make
sure it showed HOT when the engine was HOT.

Edward

At 07:57 PM 7/6/2010, Paul Guzyk wrote:
>My 1.9 style dash coolant temp sender died.
>
>I replaced it with a new one.   Now the gauge reads high, about
>65%-70% when normal operating temperature instead of 50% (LED dead
>center) like the old one.
>
>I'm thinking of adding a resister in series with the new temp sensor
>to get the needle back in the middle.
>
>Anyone seen this before?
>What value resister/pot did you add?