Howdy, I have an electric fan in front of the radiator in my 1995 GMC K2500 Suburban. Yesterday I hauled a trailer weighing about 7,000 lbs. It was a hot afternoon and the truck temp went to about 230º. When I shut the ignition off the electric fan went off too. When I turned the key on but not the motor the fan came on. I think the fan needs to come on when the motor is hot without the key on, right?