Derale Thermostatic Fan Controller
 

I recently installed a Derale electric fan controller on my truck. Here is the description off of Summit Racing's site:

"DER-16749 Thermostatic Fan Controller, Adjustable 150-240 Degrees, 3/8" NPT Probe"

http://www.derale.com/img/16749adjust_mptprobe.jpg

This kit has a 3/8" NPT probe that threads into an intake/head port instead of jamming a probe through the radiator fins. It is also adjustable and can control one or two fans. There is also a provision for tying it into an AC system so it always runs when the AC compressor is running. I don't have AC so I ran that wire to a toggle switch so I can turn it on manually if I want to.

I'm very happy with it so far and it was pretty easy to install.

Well worth the $40 price tag in my opinion!