Yes, tanks inc is wrong. Your rides uses a thermostatic gauge, not an electromagnetic one,
Essentially, your gauge has two heated bumetallic strips inside that controls the needle by varying the readings based on the two inputs from the sending unit. Without both inputs the gauge doesn't work properly. With the more common, today, electromagnetic setup it uses one magnetic field and a spring. The spring wants to move it to zero, the field wants to move it away from zero based on the strength of the magnetic field.
Pages from Chrysler Shop Manual C28 C30 C33.pdfPages from 1950 Gauges.pdfv 1.17 MB · 24 downloads