Coolant Temperature Gage

Two coils also operate the coolant temperature gage. Battery voltage is applied to both coils. One is grounded directly and the other is grounded through the indicator Engine Coolant Temperature (ECT) Sensor. The indicator ECT sensor has 55 ohms resistance at 127°C (260°F) and resistance becomes greater at lower temperatures. It has approximately 1400 ohms at 38°C (l00°F). This varying resistance causes the current through the indicator ECT sensor and one coil to change as the coolant temperature changes. This moves the pointer.