This is also something that the repair shop should take a look at for you. It is possible that the temperature sensor (this is what tells the computer to turn the fan on) is bad but that is unlikely. Since you just had work done on the cooling system it is probably a problem with the coolant level. Click here to post comments. Join in and write your own page! It’s easy to do. How? Simply click here to return to Ask Me a Car Question. footer for Auto Repair page.