AC Compressor

The AC compressor (also called the AC pump) is the 'heart' of the air conditioning system, moving refrigerant through the system.

Different ways to diagnose and detect AC problems

The AC compressor is connected with other system components, and it can cause the problem with your vehicle. There are several simple ways to check if the AC compressor is working or not. If you determine the AC compressor fault at the beginning, you can save a lot of money on repairing it.

Examine air flow Issues:

Sometimes it can happen that you are not getting enough air through the vents. One of the reasons of that can be dirty or totally blocked air filter . The air filter, even if it is not the same as the engine air filter, can blow the air slowly. Another common problem can be a broken blower motor. That’s why you should never rush to replace the AC compressor, always check your vehicle's fuse box for air flow problems first.

Check everything first:

If you are not sure that the problem is in the AC Compressor, then check the entire system. Turn off all the noise producing accessories in your car and turn on the AC. If you hear a strange sound coming from behind the console panel or inside the engine, then the problem is in your vehicle’s AC. Also good to check how cold is the air which is coming from the AC. Another sign of a faulty component or bad fuse can be a bad smell.

Take your AC's temperature:

When we have a fever, the thermometer shows us our body temperature, same for the car’s AC temperature, the AC compressor is the central part which helps to diagnose any problems. It’s all about the compressor clutch. While the AC is working, find the location of the AC compressor and the compressor clutch. This clutch is a small circular gear which helps engage the compressor belt. If the AC compressor clutch is not moving when the AC is working, then the problem is in the compressor. In this case, you can apply more tension to the belt or to replace the AC compressor itself.

Find those leaks:

If the AC refrigerant leaks, it can damage the whole AC system. Its temperature may vary or will stop the AC to work entirely. But not all the time.


It’s very hard to answer this question. They don’t have a specific mileage rating, or even performance attributes to rely on as the tires do (75,000 miles), or even car fluids like oil have a clearly defined shelf life (3,000, 5,000, sometimes 7,500 miles), for example. Anyway, you can have an idea about how long your AC compressor will last just knowing some information about your car and the way how you drive it. Let’s see some examples about when your AC compressor can fail.

  • Of course, first of all, it depends on your vehicle’s age. If you are driving only two years old car, you don’t need to worry about the AC compressor failure. If you drive some older vehicle, you will need to replace it soon.

  • It depends on a climate as well. Usually we overuse our AC in summer times when it’s getting too hot, for example in areas like the U.S. Southwest (Arizona and Nevada) and Deep South (Mississippi, Alabama, Texas, Alabama, Georgia and Florida), but some drivers turn on their AC even in low temperatures outside which of course can cause to the AC failure faster.

  • It also depends on the way how you drive and how you take care of your vehicle. Everything depends on you. For example, if your tires get worn out, the brake system will improve performance terrible as well, if you forget to change your oil, then it will cause several problems. Same for the AC compressor, always pay attention to the fluids, other component, wires, and other car parts.

  • Keep an eye on a coolant level. If there is a little or no coolant at all in the AC system, it can bring your AC compressor to fail. Always keep the coolant reservoir full.

  • The AC compressor and the radiator are connected to each other, that’s why if you are having a problem with your radiator, then the AC compressor can fail as well. The radiator thermostat can cause to the AC compressor failure as well.

AC Compressor failure

Let’s look at the most common AC Compressor failures:

  • For example, if there is no oil in the engine, your engine seizes. Same with the AC Compressor. If in the AC Compressor is missing oil, then it stops working. You will start to hear a squealing noise if your AC compressor is seized.

  • If there is any leak in the AC compressor body, or adjacent hoses and fixtures, can bring your AC compressor to fail. This failure is not so noticeable at the beginning, but slowly slowly it will become a massive problem with the AC compressor. That’s why always check for refrigerant leaks.

  • Problem with the compressor clutch. We already talked about its function above. If the compressor clutch stops working, the hot air will not be produced in your vehicle. The AC clutch failure can cause another problem with entire systems of your car. If the clutch fails, you will start to hear a squealing noise.

AC Compressor maintenance

The AC compressor doesn’t fail so often, but you shouldn’t ignore its maintenance to prevent it from a possible failure. Here is some advice on how to keep your AC compressor working correctly.

1. Even if you live in colder places where it is not necessary to use your AC, it’s always recommended to run it in purpose to make it last longer. You will just need 5-10 minutes per month to give your AC compressor a proper “workout." Turn on the AC at least once per month. Even if it’s too cold outside, leave your car with the AC on, but make sure that your vehicle is in park and the emergency brake is engaged.

2. It is recommended to change the AC compressor belt. The belt replacement will save you not only from the AC compressor failure but also from other damage of engine components.

AC compressor replacement

If you have noticed that your AC compressor is worn out, try to replace it as soon as possible. As most of the vehicles now are equipped with an air-conditioning system, the AC compressor is the most important part which starts the AC cycle and therefore, that’s why if it fails, it decreases the efficiency of the AC system. A damaged AC compressor will just waste the power generated by the engine of your vehicle.

The AC compressor can fail internally or externally. Externally it can fail due to the clutch and pulley. If you determine the compressor’s failure correctly, you’ll avoid a headache. Usually, the clutch engages and disengages the compressor when it’s required. If not, then the problem is in the AC clutch, and it needs to be replaced immediately because the clutch replacement will cost you much less than the compressor replacement itself.

In the process of diagnosing the problem, you found out that the AC compressor has failed internally, then you will need to replace the whole AC compressor.

You can replace the AC compressor by yourself if you have done it already before. This way you will save many on labor cost and you will need to pay for the part only.

Sometimes the problem with the AC compressor can be because of the debris or metallic impurities collected on it. That’s why before replacing it, flush the AC system. Flushing the system will remove any such deposits in all parts of the AC system. Before replacing the AC compressor, always make sure that all other future failure is avoided to make your car run longer and to save your money.