The 2000 Chevy Malibu comes equipped with an engine coolant level monitor that lights up a warning light when the coolant level in the radiator gets low. A common problem with this system is an inoperative light, or a light that doesn't go out even though the level is corrected. This simple float type sensor can be easy to troubleshoot. Common tools for electrical system diagnosis are needed, but the average home mechanic can diagnose this problem in just a few minutes.
Remove the radiator cap. Check and top off the fluid level in the radiator. Allow the engine to cool before removing the radiator cap to prevent serious burns from hot engine coolant.
Turn the ignition key to the run position and tap the radiator near the coolant level sensor located on the passenger side radiator tank. Check the light on the dash. If the light is now off, the sensor is sticking and needs replacement. A lack of preventive maintenance to the cooling system can cause buildup on the sensor.
Unplug the electrical connector on the coolant sensor. Check the light on the dash again. If the light is now off, the sensor is shorted and in need of replacement. If the light remains on, trace the wiring from the sensor to the dash to locate the short to ground that is causing the problem. If no damaged wiring or short is found, replace the instrument cluster. This is rare, but occasionally the instrument cluster will be the source of the short that is causing the light to stay on.
