Integra LS Coupe L4-1834cc 1.8L DOHC MFI (1997)
Coolant Temperature Gauge: Description and Operation
ENGINE COOLANT TEMPERATURE GAUGE
The Engine Coolant Temperature (ECT) gauge has two intersecting coils wound around a permanent magnet rotor. Voltage applied to the coils, through
fuse 15, generates a magnetic field. The magnetic field, controlled by the ECT gauge sending unit, causes the rotor to rotate and the gauge needle to
move. As the resistance in the sending unit varies, current through the gauge coils changes. The gauge needle moves toward the coil with the strongest
magnetic field. The fuel gauge works the same way.
The ECT gauge sending unit's resistance varies from about 137 ohms at low engine temperature to between 3O-46 ohmsat high temperature (radiator
fan running).