My $50 Flex-a-lite fan and $25 switch lasted 2+ years until I sold that particular Jeep. It never once went into the red on the temp gage and I never touched the control once I had it set where I wanted it. I'm not trying to be argumentative; y'all should mod your rigs any way you see fit. If you want to spend the money to have a digitally controlled, 2-speed, Ford made, 30 amp fan, have at it. I guess my only point was I did it for less money and seemingly a lot less effort than some say they needed to make a junkyard part work reliably in their Jeep. Also FWIW, I ran the ground on the relay through the firewall so in case it shorted, the fan would come on rather than vice-versa.
I love sleep. My life has the tendency to fall apart when I'm awake, you know?