The condenser fan relay is the electronic relay that controls the power to the AC condenser cooling fan. When the relay is activated the AC condenser fan is switched on so that it can keep the AC condenser cool. The AC condenser is designed to cool down and condense incoming refrigerant vapor into cooled liquid and uses the fan to help keep it cool. The fan's power is controlled by the condenser fan relay. Usually a faulty condenser relay will display a few problems that can alert the driver that a potential problem has occurred and should be serviced.
AC blows hot air
One of the first symptoms commonly associated with a fan relay is an AC that blows warm air. If the AC condenser fan relay fails, the AC condenser fan will not receive power and will not be able to cool the AC condenser. This may lead to a condenser that runs too hot and cannot cool the refrigerant enough for the AC to blow cold air.
Engine overheating is another symptom of a potential problem with the condenser fan relay. The AC condenser serves as the heatsink for the AC system, and can get overheated quickly, especially on hot days. If the condenser fan relay fails and the disables the AC condenser fan, the condenser will not have any means to keep itself cool and can overheat. In severe cases, the overheating can spread to other parts of the vehicle and cause the engine to overheat, putting the engine and AC components at risk of damage.
The condenser fan relay is a simple relay, however, it plays a vital role in the proper operation of the AC system. If you suspect that your condenser relay may be having a problem, have the vehicle inspected by a professional technician, such as one from YourMechanic, to determine if the car needs to have the condenser fan relay replaced.
This article originally appeared on YourMechanic.com as Symptoms of a Bad or Failing Condenser Fan Relay and was authored by Ed Ruelas.