Cooling fans always on?

[nuchieboy]

for some reason even when my car is cold the cooling fans turn on and dont seem to shut off...what could possibly be the problem?

[camryvibe]

I have the same issue with my '87 Nova/Corolla I'm pretty sure the problem is a defective temperature sensor/relay that controls the fan operation based on the radiator temperature. But the sensor/relay isn't very cheap and the extra fan operation doesn't seem to noticeably affect mileage, engine warmup, or any other function. So I haven't bothered to replace it yet.

[nuchieboy]

yea but i want to get it fixed....any other ideas?

[camryvibe]

Check the temperature sensor that's plugged into the radiator. It should be a closed circuit (almost zero resistance) when the radiator is cold and an open circuit when it's hot. If that's the problem then get a new one and replace it. Otherwise check the wiring that goes to the sensor. Any bad connection or break in the wire will make the fans run all the time.

[nuchieboy]

theres 2 sensors on one side and one on the other so i guess i have to check all of them? how much would a normal shop charge me to fix this? and also how much is the part? thanks