What does this switch do? The other day after driving to work my radiator leaked about a quart. before I left for home I filled it up and found this electrical connector loose. Would this cause the radiator to overflow? The car has become my regular transportation due to it's awsome mpg, plus it's just plain fun to drive!

 

The auxillary fan switch turns the radiator fans on and off once coolant reaches a certain temp. It should be tight on the radiator, and will definitely cause a leak if not.

 

Thanks doc, the switch itself is on tight, it was the electrical plug that was loose.