What is the best way to wire up a fan so that I dont physically have to flip a switch. Is there a switch out there that will kick on the fan at a certain temp?
Wire in a relay that turns on a light on the dash when its OFF or has no current going to the fans. This is very handy if you blow a fuse and loose the fan. It doesn't take long to over heat when your in the tough stiff and you mind is elsewhere. Don't ask me how i know!
You can also get a buzzer that runs off your gauge (electric) that goes off once the voltage reaches a set level. it just spices into the wires from the sender.
Jegs, Summit, and most auto parts stores have thermostat controlled relays. Seach here and on Pirate for diagrams. I did all that, wired one up myself. It was easy and worked great. The next time, I got a variable speed control from http://www.dccontrol.com/. It was really plug and play. Easily adjustable and becuse of the variable speed, there are no voltage spikes when the fan kicks on and off. I've been running it for about 6 mos. Love it. FWIW.