95 Saturn Low Water Light**?

When the motor is stone cold and radiator filled as full as possible. The white plastic coolant recovery reservoir is supposed to be half full with a 50/50 mix of the factory recommended antifreeze and distilled water when the motor is cold. The low coolant level gets its reading from the recovery bottle not the motor.

Read how to care for your cooling system in the manual in your glove compartment. It'll explain how the system works. The specifications conserning which antifreeze to use is in the specifications section in the book also. If the system has never been drained flushed and cleaned warm weather is the time to do it. Then and only then you will know it's got the correct antifreeze in it.

There's a big difference between a simple overflow bottle which no car has and a coolant recovery bottle which every late-model car and truck does have. Their functions are entirely different.

The low water light sensor is in the reservoir. The overflow needs to be filled to shut the light off.

The reservoir needs to be filled to the full level. The sensor is inside the reservoir.

No, the reservoir needs to be at the proper level then the light will go off.