I have Contour fans and a Dakota Digital controler. I'm using the factory harness on the fans with the resistors (I installed a new one from ROck Auto.) I have my fan controller set to run two seperate fans. The fans come on at low speed as fan one, then they come on high as fan two. I have a 70 amp relay on the low side, and a 40 on the high side. I used the 70 amp on the low side because while being lower draw at low speed, that is where the in rush load is to start the fans. Been running this way for a year and a half, and works great.
1993 Mustang LX Coupe H/C/I 306/T5/IRS
1997 Lincoln Mark VIII