In light of the recent popularity of running factory 2 speed fans like the Taurus and the Mark VIII, I have started building custom fan wiring kits designed for these HO fans using a PWM variable speed voltage controller and a 4 relay system using an integrated manual override/kill switch for the controller in case of a failure. No kit on the market is designed to take advantage of the 2 speed fans because nobody on the aftermarket even makes that style of fan. I've been building these fan kits for quite a while and I am always looking for ways to improve them. So now, these kits I've come up with allow you to program two temperature ranges where one is the low speed fan, the other triggers a relay for high speed fan that runs through a HD relay and another acts as a shut-down for the unit itself. You also have an AC over-ride feature, and you can change the temperature settings as you see fit. If anybody is interested, email me with requests on how to either modify yours or switch to this setup. You can use this kit with any single, 2 speed fan but it is geared towards high CFM fans and all the components are heavy duty!!!