Temperature Gauge
Temperature indicating system consists of a variable resistance sending unit, Instrument Voltage Regulator (IVR), and gauge. As coolant temperature increases, resistance in sending unit decreases, allowing an increase of current flow and gauge pointer movement. It is possible, under certain driving conditions, for pointer to read at top of normal band and still have coolant temperature within limits.
NOTE:
On models with Automatic Temperature Control type air conditioning systems, the temperature sending unit has 2 terminals. The terminal marked "R" (gauge equipped) or "C" (indicator light equipped) provides a ground circuit for cold engine override (below 115°F or 46°C engine temperature) of heater blower motor.