Coolant Temperature Gage

The 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 Coolant Temperature Sender/Switch. This has 63 ohms resistance at 125°C (260°F) (hot coolant) and its resistance increases at lower temperature. Resistance is approximately 1365 ohms at 40°C (100°F). This causes the current through the sender and one coil to increase as the coolant temperature increases. This moves the pointer.