Most dual fans require a controller or relay setup of some sort to operate. Plus, you'll need 2 different temp switches to turn them on if they are different speeds. So most of the triple relay setups sold out there you lose 1 relay, you lose it all from what I was told. That is even the Hollister setup which someone sent me all the information for. So this is the budget setup to ensure the lowest cost up front and best results for both a dual fan setup, or a Taurus 2 speed fan setup. #1. You need 2 temp switches for 2 speeds. Solution = BMW 91 / 99* C (180/195*F) dual temp switch Part # 61311378073< $11 from Rock Auto - can't beat that. One single temp switch instead of 2, just gotta drill and tap a brass adapter fitting to accept the M14 x1.5 thread. http://www.nastyz28.com/forum/showthread.php?t=196209 #2. Heavy duty controller for 2 speeds. (Thanks Onovakind67) 94-97 850 Volvo vehicles used a heavy duty relay dual fan controller part # 1398845 http://www.nastyz28.com/forum/showthread.php?t=192920&highlight=volvo Volvo Controller = $10-$20 Salvage yard or ~$50 new. BMW Dual Temp Switch = $11 Here's the simple schematic , You can optionally wire in 2 LED's so you know when each fan is on.