Symptoms of a Faulty or Faulty AC Thermistor

If your car's air conditioner only blows cold air for a short amount of time or the fan is not working properly, you may need to replace the AC thermistor.

An AC thermistor is a type of temperature sensor commonly used in modern AC systems. They sense the temperature and send a resistance signal to the A/C control module so that automatic adjustments can be made to maintain the correct cabin temperature. Since they are basically ambient temperature sensors, they can be found both inside and under the hood of a car.

AC thermistors read and interpret temperature data that is critical to the correct operation of a computer controlled AC system such as found in most modern cars. When thermistors fail or start to have problems, they can negatively affect the operation of the entire system and should be checked. Usually, when an AC thermistor fails, they cause several symptoms that can alert the driver that there is a problem.

Limited cooling

One of the first signs that the AC thermistor may be having problems is that the air conditioner will only blow cold air for a limited period of time. If the AC thermistor is not working properly, it cannot warn the computer of the cabin temperature. Therefore, the module will not be able to activate or deactivate the air conditioner so that the correct temperature can be reached. This may cause the air conditioner to blow cold air in short bursts or only for a limited period of time.

The fan will not work properly

Another sign of problems with the thermistor will be problems with the fan. Some fan motors use a thermistor signal to control their operation. If the thermistor gives an incorrect, weak, or inconsistent signal, the fan motor may run weak, erratic, or not run at all. Because the fan blows air out of the vents, any problems with the fan, whether caused by the thermistor or not, will greatly affect the air conditioning system's ability to cool the passenger compartment.

Since AC thermistors can play such an important role in the correct operation of the AC system, if you suspect that you may have a problem with it, contact a professional technician, such as the one from AvtoTachki, to diagnose the AC system. If necessary, they can replace the AC thermistor and restore full functionality and performance to your AC system.