What does a condenser fan relay do?
Think of the relay as a signal that tells the air conditioning’s condenser fan when to turn on and off. You might hear this part called the cooling fan relay. The relay provides power to the fan in order to pull air through the radiator and condenser. Then, when the fan motor reaches a certain temperature, the relay tells the cooling fan to turn off. In some vehicles, the condenser fan works in tandem with a radiator fan—and both are powered by relays.
If the condenser fan relay is broken or damaged, it might not work at all (causing engine overheating), or it will be permanently stuck in the on position, which can disrupt airflow in the cabin.
How do I know if my condenser fan relay is bad?
If the air conditioner doesn’t work on a regular basis or it stops working entirely, the relay might be to blame. Here are more specific signs of a bad condenser fan relay:
The AC blows warm or hot air: If the relay goes out, the condenser won’t get the necessary power to stay cool. As a result, it will blow warm air because it can’t cool the refrigerant enough.
The engine overheats: This happens if the relay fails and disables the condenser fan. When the fan can’t cool itself, it overheats, which causes the engine to overheat, too. To avoid costly repairs, get your AC inspected as soon as possible.
The condenser fan makes a rattling sound: If you know your way around the condenser fan and remove the relay, you may hear a rattling sound if you shake the relay. This means the relay itself is broken.
How often should a condenser fan relay be replaced?
The condenser relay fan is the component of your AC that’s most likely to fail. Over time and with lots of use, the relay fails and could get stuck. As soon as the relay starts acting up and you notice the AC isn’t effectively cooling your car, it may be time to replace it.
Keep in mind: The condenser fan relay is not usually inspected during tune-ups or regular maintenance. If you suspect something is wrong with it, ask a technician to check it out.
Can I replace the condenser fan relay myself?
If you’ve got DIY automotive skills and feel comfortable working with your car’s fuse box, you should be able to swap out the condenser fan relay. However, if you’re not completely sure that the relay is causing the problem, get a professional inspection or have the mechanic service the AC. Working with coolant requires specialized training and certification, so it’s best to have a professional troubleshooting and repairing your AC system.