Coolant Temperature Gauge

The Engine Coolant Temperature Gage is operated by two coils. Battery voltage is applied to both coils. One is grounded directly and the other is grounded through the Engine Coolant Temperature Sender. This has 54 ohms resistance at 125°C (260°F) (hot coolant) and its resistance increases at lower temperature. Resistance is approximately 1254 ohms at 40°C (100°F). This causes the current through the sender and one coil to increase as the engine coolant temperature increases. This moves the pointer.