Temperature Gauge: Description and Operation

The Coolant Temperature Gage is also operated by two coils. Battery voltage is applied to both coils. One is grounded directly and the other is grounded through the Coolant Temperature Sender. The Coolant Temperature Sensor has 55 ohms resistance at 260°F (125°C) and its resistance increases at lower temperatures. Resistance is approximately 1365 ohms at 100°F (37°C). This causes the current through the Coolant Temperature Sender and one coil to increase as the coolant temperature increases and moves the pointer. When the Ignition Switch is moved to BULB TEST or START, the pointer moves through its full scale.