When I turn the ignition to on , but do not start the car i can hear one of my fans running, and when I start the car it is still running. Once and a while it dose not come on when I turn it to on or start it. Any idea to what the cause could be?

 

Hmmm, not sure, but possibly the temperature sensor. It could be sending false signals to the ECM which would turn on your fan at a certain temperature. Not too sure, but it's worth a shot. Put a scan tool on it if you have access to one. Hope this helps.