temp
That wire is coming from a switch, not a sender. The switch stays open as long as there is no problem, but when the temp rises above a preset number, the switch closes and sound the alarm. You'll need an actual sender, which is just a variable resistor. You'll need the gauge and sender from the same maker, it doesn't matter which, but you may need an adapter to screw into the block. In some cases, you'll need to make your own by soldering/brazing/screwing some threaded parts together.