There is some information in the attached document starting on page 180...showing the range of resistance of the temp sender:
The engine coolant temperature sensor is a variable
resistor, providing a ground circuit path for the temperature
gauge. As the engine coolant heats, the resistance
decreases. As the resistance decreases, more current is
allowed to flow across the engine coolant temperature
gauge causing the needle to rise and indicate a higher
temperature. The temperature gauge is part of the
The engine coolant temperature sensor resistance is
approximately 40 - 700 ohms.
...and the nominal voltage at the panel gauge when engine is not running:
3. B2 Engine CoolantTemperature Switch -- 6.0 to 7.0 volts
Test B2 Engine Coolant Temperature Sensor (See Temperature
If the switch is OK and the P2 Coolant Temperature Gauge
does not operate correctly, replace instrument panel.
Here is the section excerpt of the document:
X495 electrical op and diag from TM2024.pdf
...Bummer if you have to replace the dash module...looks really expensive!