Expert: Sean Halliday - 6/10/2006

Question
i have a 93' ford probe gt 2.5L v6...i've had to replace the engine because of overheating...the reason it overheated was because the radiator cap wasnt on all the way. i KNOW for a fact that my fan does not kick on at all though. i checked my fuses and they're good. what am i going to have to get replaced or checked? doesn't that one wire or connection run a/c and something else including the coolant fan? when i turn my a/c ON, my car idles down instead of up and it seems like it wants to kill.  

Answer
no,the one wire is for a/c only.you have a thermostat controlled switch usually on either the radiator or the thermostat housing to turn on your fans,one will work for the engine and both will come on when the a/c is on.so,,,,,,you have a bad sensor for the a/c idle,,,,,,,,,,it should idle up and you should replace this sensor,its usually on the throttle body or near it,,,sometimes the firewall  .as for the fans,,,its relatively cheap to buy the sender switch and when you replace it just let the car idle and watch to see if they come on,,,,,,the fans that is,,,on the back of your fans when you look it will have 2 harnesses for both fans or one if equipped sometimes different cars have 2 or maybe just 1,,,,,but you will have wires going to the fan,,,,on the bottom of the radiator or the thermostat housing is where you will see the sender unit,its usually about the size of a quarter in diameter,it screws in ,,,hope this helps,,