Temperature Sensor Questions

[Camacorn]

Okay, my temperature gauge on my 1986 C10 hasn't worked since I purchased it. I tried all of the basics, such as grounding out the cable, and I have confirmed that the gauge works, and the wiring is okay, so this leads me to the temperature sensor itself.

I'm trying to test the sensor to see if it works, but I need to know: If I have the sensor out of the block, and I place it in boiling water with the wire connected ( but not submerged ), should the gauge move, or does the sensor have to be grounded as well as connected to the gauge to work?

And if so, what part of the sensor do I have to ground?


Thanks!