Check to see if the cooling fan turns 'on' when the A/C is on -- and check if it turns off when the A/C is turned off.I am assumeing it does.
Your engine cools itself by absorbing heat into the engine coolant and dissapating it to the outside. It does this by pumping coolant through the radiator and the heat is blown off by the cooling fan (as it blows air over the fins of the radiator).
The cooling fan is a VERY important item when it comes to cooling your engine. It is turned on two different ways -- #1. When the A/C control is turned on the fan should automaticaly turn on - thus cooling the coolant that is being pumped through the radiator which cools the engine.
#2. The cooling fan is also controled by the coolant temperature sensor (or sensors). When the coolant reaches a certain temperature, the coolant temperature sensor - switches the cooling fan relay - which turns on the cooling fan. Number 2 is probably where your problem is. Check the cooling fan relay. If it is good, then replace the coolant temperature sensor (CTS). Be sure to replace the sensor that controls the cooling fan -- there is another sensor that sends a signal to the temperature gauge. This sensor has nothing to do with the cooling fan control circuit.
Saturday, July 17th, 2010 AT 9:41 PM