Coolant Temperature Gauge

With ignition switch in RUN position, gauge indicates approximate engine coolant temperature. Gauge has 2 magnetic coils which pull on pointer in opposite directions. This balancing effect of the coils prevents possible errors resulting from varying battery voltage. Both coils have voltage applied directly and "cold" coil is permanently grounded. "Hot" coil is grounded through Engine Coolant Temperature (ECT) sender. Resistance of the ECT sender is high when coolant is cold and resistance is low when coolant is hot.