Temperature Switches

This switch is mounted in the cooling circuit, usually at or near the radiator, and operates with the temperature variation. There are two types of switch:

• Alarm Thermocontacts

• Fan Thermocontacts

Alarm Temperature Switch

Is a system which performs a control of the engine temperature. Informs the driver of a wrong engine temperature by activating a light signal, located in the dashboard, when the engine exceeds the calibration temperature.

Fan Temperature Switch

• Monitor the engine operation temperature

• Connect / disconnect the radiator fan in order to control the engine temperature

• Achieving optimum engine performance

The good condition of the metal body, the connector and wires must be checked and ensured.
Also verify if the sensor shows any cracks, dents or impacts that might have damaged it.
Keep in mind that, as a general rule, visual inspection is not sufficient to ensure the good or bad performance of the part, but it helps to make an initial diagnosis.

1. Cracks or breaks. Tensions provoked by mechanical stress

2. Deformation and denting. Overheating of the sensor.

3. Leaks. Bad anchored sensor to the engine block or a worn out seal

4. No signal. Failure of the wire due to friction or excessive vibration, short circuit, internal failure of the sensor due to mechanical or thermal stress

SIGNS OF FAILURE OF SENSORS

• High fuel consumption

• Power loss

• Overheating

• Warning light Engine Check.

• Difficulties starting the engine

• Increased emissions

SENSOR MAINTENANCE

The specific values of the sensors must be checked each maintenance or every 25.000km. Remember that refrigerant can cause corrosion and disable the res- ponse of the sensors. In case of air sensors the possibility exists that impurities obstruct the pipes which results in the impossibility of performing readings by the sensor. Replace the sensor whenever results are diagnosed which are not within the specified operating limits.