another reason for a car to overheat

another reason for a car to overheat is the failure of the radiator fan to operate.  the function of the radiator fan is to suck the heat in the radiator fins and blow it to the engine.  you will notice that the direction of the air being blown out by the radiator fan is NOT TOWARD the face of the radiator.

the operation or the triggering of it to operate is controlled by a switch.  normally this switch is screwed  to where the end of the lower radiator hose is placed or sometimes this switch is screwed at the lower casing of the radiator.  this location is best suited to the switch because , those two locations receives water after it passes the cooling fins of the radiator.

this switch , just like the thermostat, is preset to a certain water temperature, that means that switch will only activate the moment it sensed  the water temperature set for that switch.

normally, this switch has a two wire connection placed in a socket terminal, one wire is connected to a ground and the other one is connected to a  RELAY .   In the event that it reaches the desired water temperature, the grounded wire will be touching the other wire on that socket, thereby supplying a negative power to the relay that would trigger  a winding on that relay  to supply a positive power to the RADIATOR FAN which other wire is grounded.

when a car overheats, shut of the engine immediately.  But  Switch on the ignition switch to the ON POSITION.
Open the hood, and see if the radiator fan is running or moving, if not then , two things have happen:

   1. the radiator fan is defective
  2. the switch is defective.

HOW CHECK WHICH ONE IS THE DEFECTIVE.

1. remove the socket terminal of the temperature sending switch or the switch as mentioned above.
2. put a jumper wire on both female terminal of that socket .
3, switch on the ignition switch, if the fan operates , then it is the temperature sending switch is the one defective.
4. if the fan did not operate , the it is defective.

Make sure that the corresponding fuses of the fan is not busted.
WHAT TO DO IN THIS SITUATION.

If the sending switch is defective , continue the jumper wire to be connected, then continue driving the car.
If the radiator fan is the one defective , then you have no choice but to replace it unless you have no choice but to continue driving  but make sure you have enough supply of water in your car so that you can pour water over the radiator.

IF IN ANY EVENT THAT THE TEMPERATURE NEEDLE ON THE TEMP GAUGE DEFLECTS TO THE TOP but  the fan is operating or moving and  engine is not overheating as you feel it then most likely the temperature sending unit , ( this where the temperature gauge is connected)  is the one defective or even the gauge itself is defective.  What is important in this situation is the engine itself is not overheating, so you can continue with your trip but later on you must replace the part which is defective..

if the temperature gauge sometimes go up and go back to normal ,  it is probable that the thermostat is not functioning properly or normally.  In this case , you might as well remove the thermostat and have the car runs and observe if the symptoms would still persist.