I run a nifty, narrow (3.25" thick!) dual fan set up that comes all self contained with shroud, wiring, and two fans. It is out of a 2,000 Ford Contour, and it is a bear to remove. I should say that I would have used a Taurus or Volvo fan if possible, but since I have 4.9 inline engine, there's not much room between the radiator and w/pump pulley, so I went with the Contour fan which is very popular with the Mustang fox body guys. I used to travel through Baja to fish, and needed a powerful, dependable fan. When I read about a guy with a big block in his truck who used this fan to drive cross country, I was sold on this fan.

Thin and compact 2x 12" fans.

This is the resistor that Ford uses to create a low speed with the Contour fans.


Had I used the Taurus or Volvo fan, I could have used several inexpensive control systems like the volvo relay pack ($10 in the j/y) with a thermo switch, and that would have allowed me to use low/high speeds of both of those fans. But, the Contour fans are not true 2 speed fans. But Ford wired them in a way to make them 2 speed. Let me explain: Normal 'on', without the A/C, is wired through a resistor that drains power to the fans and produces a slower fan. However, when you turn on the A/C the fans get direct, full current for 'high' speed. Since the power drain is the same with or without the resistor, I chose not to use it. But the jump right to full power caused a spike and that caused my ignition to hesitate, so I searched for an alternative system. Then I heard of PWM, pulse width modulation control that starts the fans to spin slowly with a 'soft start' and increases or decreases the rpm of the fans according to the engine coolant temperature. It sounded like just what I needed and I started to do research about the various controllers out there.


This is how to wire the Volvo relay controller to a 2 speed fan. The 4x guys love the on/off toggle switch for river crossings.

The well-known Volvo relay pack works with a thermo switch. When coolant reaches a certain temp the fans turn on. If temp climbs higher, low speed is turned off and high speed is activated.


Above is the volvo controller connected to a BMW thermo switch that has been installed into the side tank of a radiator. Many guys will buy a metal sleeve and install the switch into a bung in the sleeve, and then install the sleeve into the top hose of the radiator.


Finally I chose to go with a controller made by an army trained electrician. He sells the controllers online at autocoolguy.com. He makes them in his garage and I like to send my $ to the independent guys. Of course, I hadn't come across any negative reviews like I did with the controllers made by the big companies. I am not affiliated with ACG in any way. I just like his product. I have used it for more than a year now without issue. My fans now start without my even knowing it, and keep the temp right at the temp of the thermostant.

The one thing that bothered me a bit about the ACG unit was that he uses his own thermo switch that is connected, spliced into the LOWER hose of the radiator. I thought that it should be regulating the temp of coolant coming out of the engine, and that meant splicing into the top hose to sense the temp of the coolant leaving the engine. But the ACG insists that monitoring/controlling the temp of coolant entering the engine is a better system. I realized that either way the temp of the engine coolant is regulated, so I'm okay with it.


I went with the adjustable, 85 amp autocoolguy controller because my fans only draw a total of 30 amps.

 

nice writeup!

 

Very informative tech, thank you for the info. And X2 very nice write up and now I have to find a 2000 Ford Contour with a fan system that it is a bear to remove. To save some time, where is the "resistor that Ford uses" located?

 

The resistor is housed in the shroud. You can simply leave it there and not use it since the controller gives you a nice soft start without the big current spike.
Since these fans are so popular with the fox body mustang guys, there are installation kits out there. If interested, just dig around a google search for the fan and you should find the kit and lots of info.
Another fan I really like, for those with more room up front, is the two speed Volvo fan. It can actually be removed from the shroud so that it can be placed into a custom shroud.


From back when Ford owned Volvo. Notice the screws that make the fan removeable.