1> Listen for the Compressor: When the AC is turned on, go outside to where the compressor unit is located. You should hear a low hum or steady noise coming from it. This indicates that the compressor is running. If you don't hear anything, it might not be functioning.
Warm Air from the Vents
If the compressor is fine, it will push cold air into the cabin of your vehicle. If you begin to notice warm or even hot air coming out of the vents, this is a clear indication that the compressor is not functioning properly.
If the center of your a/c compressor is turning while the engine is running then it is engaged! You will also hear a definite click when you press the a/c button and if your compressor is working well you should see a definite drop in rpm when engine is idling and you switch on your a/c. About 50 rpm.
Your air conditioner compressor is making unusual noises: If your compressor is making a loud rattling, grinding, or clicking noise, this could be an indication that a piece has broken inside it. If it is more of a grinding noise, the compressor bearings might need to be replaced.
Still, if your compressor is bad, you may not even notice anything initially. An air conditioner with a bad compressor can still run as soundlessly as the next machine, an obvious lack of temperature control aside.
A good indicator that your AC works efficiently is if the ambient temperature drops at least one degree every 20 minutes. As an additional note in keeping your AC strong and healthy, refrain from overheating the home. This is not in regards to using the furnace but letting ambient temperature rise too high.
One of the reasons why compressors do not engage is because of a low pressure lockout, a poor ground, a bad clutch coil, an opening in the wire to the clutch coil, or simply a blown fuse.
Some of the obvious signs of a bad compressor include loud noises coming from the unit, water leaks around it, and reduced airflow. To fix the problem, some choose to replace the compressor, while some prefer to replace the entire unit.
On average, AC compressor costs range from $800 to $2,300, with most folks paying $1,200 for a new one. However, your price will vary depending on factors like the size and brand of your compressor. Before you schedule your replacement, read on to learn about all AC compressor cost factors.
Faulty Contactor
If the contactor is faulty or worn out, it might not send the necessary voltage to the compressor, even though the fan receives enough power to run. This can create a scenario where the fan kicks on, but the compressor remains idle.
The hum of the compressor
The most important noise you'll hear from an air conditioner that indicates it's performing its job as normal is when the compressor in the condenser cabinet starts to hum. This signals the start of the air conditioner's cooling cycle.
The first thing you'll want to do is check the thermostat. If you have air that's controlled by a thermostat, make sure a faulty thermostat isn't what's causing the problem. In some cases, the batteries may have died or the unit is malfunctioning. Reset the thermostat to see if that turns the AC unit back on.
There are a number of reasons why your air conditioner might be running but not cooling. It could be an issue with the thermostat, the compressor, or the evaporator coils. Or, it could simply be clogged with dust and debris, which is preventing it from working properly.
Place the pins on the black and red wire from your multimeter onto the terminals. Once you place the pins on the terminals, your multimeter should have an ohm reading of less than 30. Anything significantly above this reading indicates that your compressor may be broken.
The air conditioner fan is responsible for circulating cool air throughout your home. If the compressor is not working, the fan will not be able to do its job properly and cool air will not be circulated.
It pulls warm air from your home, passes it over the evaporator coils (where the cooling happens), and then distributes the cooled air back into your living spaces. So, will the AC fan run if the compressor is bad? In most cases, yes. The fan can operate independently of the compressor.
Warmer Air Is Flowing Out
When your AC turns on, you expect cool air to come out of the vents. Warmer airflow, just like diminished airflow, is also a sign of AC compressor failure. If you feel warmer air, call your professional to inspect the compressor for leaks.
Electrical Problems
Faulty capacitors or loose wiring can cause clicking or buzzing noises when the AC powers down, leading to potential risks of electrical shock or fire. Reach out to a qualified technician immediately if you suspect an electrical issue.