Hi Guys...
How do I check the cooling fan relay...? I guess there are three of them.

I think I might have a problem with relay. The cooling fans should be able to run at 2 different speeds.. right low and high

I have only seen high speed running of fan .. but not low speed..

Can any one suggest how to look for the proper operation of these relays?
Please....

 

The relay is probably fine. The fans operate at high speed if the coolant temperature sensor isn't functioning properly. You can use a multimeter and test the resistance of the coolant temp sensor.

Get a cooking thermometer, boil some water, and remove the coolant temp sensor from the car and clean it a bit. Put the sensor into the water (not the whole thing) and measure the resistance at certain temperatures. Here's the breakdown:

1) When the water is at 60 degrees, the coolant temp sensor will range about 2,100 to 2,900 ohms.
2) When the water is at 122 degrees, the coolant temp sensor will range about 680 to 1,000 ohms.
3) When the water is at 176 degrees, the coolant temp sensor will range about 300 to 330 ohms.

If you don't get similar readings, then I'd suggest replacing the coolant temp sensor.