1999 Chevy Monte Carlo

Tape the radiator cap off, if there is too much antifreeze in the radiator then syphon some out, start the car and let it idle for a while watch the temp guage. When the car has warmed up look and make sure the fluid is circulating, before shutting the car off replace the radiator cap. Before shutting the car off make sure the resevoir is full. When the car cools the fluid in the resevoir should be sucked back in. The reason I suggest this is that the engine is not vapor locked. If the circulation is good and the light still comes on check the low coolant sending unit