Trans Sport V6-3800 3.8L (1994)
Temperature Gauge: Description and Operation
CIRCUIT OPERATION
The Engine Coolant Temperature (ECT) gauge applies voltage through circuit CKT 135 to the engine coolant temperature sender and ignition
switch. The engine coolant temperature sender is a variable resistor. At 40°C (100°F) the resistance of the engine coolant temperature sender is
approximately 1365 ohms. At 125°C (260°F) the resistance of the engine coolant temperature sender is approximately 55 ohms. As the resistance of
the engine coolant temperature sender decreases, the engine coolant temperature gauge senses a smaller voltage drop across the engine coolant
temperature sender, indicating higher coolant temperature. As the resistance of the engine coolant temperature sender increases, the engine coolant
temperature gauge senses a larger voltage drop across the engine coolant temperature sender, indicating a lower coolant temperature. When the
ignition switch is turned to "BULB TEST" or "START," CKT 135 is grounded through the ignition switch, causing the gauge to indicate high
coolant temperature.
