i got a 96 V-6 with two fans. one come on with the a/c and the other works via the heat of the engine...
my 93 taurus has just one fan, but it is controlled by the a/c going on and also the heat from the engine.. the part that controls this might be the fan relay or the ECT sensor(engine Control heat sensor) check it out at either auto zone or advance auto parts.. it should cost about $15.00 for the sensor and it should be on the cross over pipe by the water pump.. its got two wires that go to it.....