This is a simplified version if you want to operate the fan manually on one speed and if you have air conditioning. I just installed my taurus fan, I used a three position rocker switch and two relays so I can operate the fan at either low speed / high speed /or off. I don't have A/C so it wasn't an issue at all. Do you have an upgraded alternator, if you have the stocker, you will need to upgrade. I am not sure what the current rating of those relay p/n's are, just make sure you get one with contacts rated for at least 40A for the high speed control, the standard relays that most places stock seem to be 30A rated which is fine for the low speed relay. The fan will draw about 15A on low speed and about 34A on high speed according to my Fluke clamp meter.
Speaking for experience, the DCC unit will keep your car at the correct temperature without you having to flip on any switches or moniter the temp gauge.
I have the DCC FK35, Mark Viii fan and 3G and no longer worry about sitting in traffic. It's a nice feeling...