Not sure if this will help, but I assume the power to the fan comes from the ignition switch. I say that because there's some members here that have wired the fan on their UTV to run constantly when the UTV is started. They do so with a short jumper wire on the temperature sensor wire plug at the radiator. With this in mind, I believe that the fan's power supply is from the ignition switch. Don't know how it's wired to supply the power to the fan, though. Maybe someone will chime in that has made this modification.