I would begin by just checking for a change in resistance with change in temperature to see that the sensor is working. I think most failures would show up as no change as the sensor heats up. In your case, I would check wiring connections and power supply first if I suspected an inaccurate gauge reading. Apples to oranges for sure but my Vanagon had a temperamental temp gauge, until I turned one of the contactor nuts on the backside just enough to break up any tarnish on the connection. Chris
For future reference, what are the resistance values for cold and for operating temperature?Chris