How do you test a condenser fan relay?
The quickest way to tell whether or not the electric fan(s) are working is to start the engine; let it reach normal operating temperature and then turn the A/C on. The cooling fan in the engine compartment should turn on to pull air through the radiator and A/C condenser.
Does an electric fan need a relay?
Most parts stores carry toggle switches and/or push-pull switches that will handle anywhere from 30-60 amps, so that would work. If you’re using one of those thermostatically-controlled deals (or a low amp rated manual switch) you should use a relay.
Can one relay run two fans?
Yes, you can control dual fans separately. You can use dual thermostatic switches that control each fan individually for example. This method requires a second temperature switch, a little additional wiring, and of course dual relays.
What happens if you have a bad cooling fan relay?
The check engine light illuminating may indicate a faulty cooling fan relay. A faulty cooling fan relay can also negatively affect air conditioning (A/C) performance. The reason being, on most vehicles, is that the cooling fan doubles as a condenser fan.
Can a radiator fan and condenser fan share a relay?
There are, however, some models that use a dedicated second unit to the condenser. In such a scenario, the condenser fan and radiator fan may or may not share the same relay. If the cooling fan does not engage, you can check whether the relay is to blame by swapping it out for a different relay.
When do you turn on the fan relay?
When the correct parameters are met, a temperature switch or the computer will activate the relay, which will allow power to the fans. The relay will usually be activated once it is detected that the vehicle’s temperature approaches excessively high temperatures.
What should the resistance of a fan relay be?
A normal relay’s resistance will read between 40 to 80 ohms. Higher resistance levels warn that the coil has started to fail while lower readings mean the relay has broken down. Still another DIY test involves shaking the cooling fan relay and listening for any noises.