[Galane]

I recently swapped the engine driven cooling fan on a V8 1998 Mercury Mountaineer with a dual electric fan from a Ford Contour and a homebrew dual speed controller.

That's the Contour with the single piece shroud, not the completely separate dual fans, which are quite a bit thicker. The fan unit mounts vertically in the Mountaineer/Explorer and is the exact length required to match the height of the truck radiator. (It's also exactly the right size to fit horizontally on many Jeep and other brands' radiators.)

The thermostat housing had a spot to drill and tap for a sensor, had to install a 90 degree brass elbow so the sensor would fit below the AC hardline. The sensor I used was an ordinary Ford ECT as used in the late 90's.

The controller has a relay setup copied from some Australian Peugeot. It switches the two single speed fans between serial and parallel connection. At the low turn on setting the fans run in series at 6 volts each. When the high setting is reached the low circuit runs only one fan while the high circuit runs the second fan.

There's a 4th relay in parallel with the AC clutch and the low speed relay so the fans run in low speed when the AC is on.

I used a pot of water on my stove and a battery charger to calibrate the high and low settings. Low turns on at 190F, high at 200F. The engine thermostat is rated at 195F, so soon as the thermostat opens the fans come on low speed.

Before doing this electric fan mod the truck averaged 15 to 16 MPG in mixed driving conditions. Now it averages 18 to 20+ Since I have well under $200 in the electric fan setup it will pay back very quickly.

An extra benefit is how much *quieter* the truck is without that big air chopper constantly whirring under the hood. The Contour fans are very quiet, even on high.