Central air conditioners use an outside condenser coil to cool the refrigerant used to cool your home. There are fins that surround the condenser coils and they get dirty over time. The fins sometimes become bent and need straightening to allow proper air flow through these coils.
For safety reasons, please turn off the power to the air conditioner by turning off a circuit breaker, fuse, or disconnect feeding it. Having a condenser come on in the middle of cleaning could be fatal.
Before straightening the fins, you must first clean the coil fin area from any debris that surrounds the condenser coil. Use a soft brush and spray the coils with water and air if they are both available.
Remove the upper cage assembly from the unit by removing the screws. The motor is connected to the cage, so lift both out of the way and look into the center of the condenser coil.
The coils should be sprayed out with a hose and a sprayer attachment. Spray the water through the coil fins to clean, spraying from top to bottom. Be sure to get the dirt sprayed from the bottom of the unit also. Otherwise, this dirt will be sucked back into the fins the next time you run the condenser.