A faulty cooling fan switch can have a variety of symptoms, all of which should be taken seriously. These symptoms include overheating of the vehicle due to the fan's inability to circulate air or coolant. Furthermore, you may notice that your car is running hotter than usual and has difficulty starting up in hot weather. Additionally, the engine could suffer from poor acceleration as well as misfiring and stalling when it is put under load. Finally, if you experience any kind of electrical issues such as flickering dashboard lights or strange noises coming from underneath the hood then this could be an indication that your cooling fan switch is failing. It’s important to take these symptoms seriously and get it checked out by a professional mechanic who can diagnose and repair any underlying problems before they become more serious and costly down the line.