I noticed my engine is prone to overheating when standing still, idling or moving slowly. I have replaced radiator and all hoses and thermostat and sensors and then I noticed that the Auxiliary Fan is not staying on, even when the car is getting hot. With a volt meter I checked the voltage on the 4 pin (3 only used) connector for the Aux Fan. It read 6.2 volts at the time I checked it. I understand that the EMC regulates the voltage to slow down or speed up the fan according to the temperature of the coolant fluid and exhaust however how can I determine which part is going out? Is it the Fan motor? or one of the relay switches or the EMC? Suggestions??? Thank you