Paul,
I would purchase a 100 ohm potentiometer.  Place it in series with the
sender and use it to dial in exactly where you want the needle. Now remove
the pot and read what resistance corrected the gauge. Try and find that
value resistor and wire it in. Now take the 100 ohm potem and substitute
the temp sender with it. Check the calibration of the gauge against the
values posted earlier.
  You've gone this far,might as well check the calibration of the sender
you bought in boiling water.
Good Luck.
Ken Lewis

On Tue, July 6, 2010 7:57 pm, 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?
>
>