Why does the radiator fan of my 2004 Chevrolet Cavalier keep on running whenever engine temperature reaches 92 degrees Celsius even if the engine is already off? The fan runs for more than five minutes. This started happening this summertime. Won’t the battery be drained? Thanks.
Answer: It happens because, it has a thermometer, along with many other sensors, and when it detects that the engine is too hot for it’s own good, it runs the fan to cool the radiator coolant. It’s a good thing, don’t worry. And no, it should have no adverse affect on the battery, because it’s sensing that as well.
That said, I had a Fiat (my bad choice, I know) that ate batteries. It turned out that my car had a broken switch once it turned on the fan, it never turned it off, and that did drain my battery, daily. Pissed me off, it took months to figure out the culprit.