Tracker 2WD L4-1.6L VIN 6 (2000)
Temperature Gauge: Description and Operation
The magnetic field of 2 coils moves the pointer of the Engine Coolant Temperature (ECT) gauge. The coils are at right angles to each other. Voltage
applies to the H coil from the IG fuse. The circuit divides at the opposite (ground) side of the coil. One path seeks a ground through coil C. The other
path seeks a ground through the variable resistor in the engine coolant temperature (ECT) sending unit.
The resistance in the ECT sending unit is high when the engine coolant temperature is low. Current flows through the H coil and the C coil to ground at
G103 because current always seeks the path of the least resistance. Because the length of the C coil winding is twice the length of the coil H winding, the
magnetic filed that coil C generates is twice as strong as the magnetic field that coil H generates. The magnetic field therefore pulls the pointer to the C
position.
As the engine coolant temperature increases, the resistance in the ECT sending unit decreases. Since current always seeks the path of the least resistance,
more current begins to bypass the C coil and travel directly to ground through the ECT sending unit. The coil H magnetic field then becomes stronger
than the coil C magnetic field, causing the pointer to move toward the H position.
