The reservoir has a floating magnet in it, that magnet is what completes the circuit via a magnetic field around the sensor when it’s in the proper position. The sensor goes up inside a plastic tube built into the reservoir and is kept separate from the coolant so it isn’t exposed to the coolant. The magnet has a hole in the center of it like a donut and goes around the plastic tube and moves up and down in accordance with the coolant level. Hope that makes sense.
The reservoir has a floating magnet in it, that magnet is what completes the circuit via a magnetic field around the sensor when it’s in the proper position. The sensor goes up inside a plastic tube built into the reservoir and is kept separate from the coolant so it isn’t exposed to the coolant. The magnet has a hole in the center of it like a donut and goes around the plastic tube and moves up and down in accordance with the coolant level. Hope that makes sense.