Something Is Wrong With My Car’s A/C! How Much Will It Cost To Repair Or Cost?

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Inside a car, the summer heat can be intense and the winter cold can be harsh in some areas. If the air conditioning in your car is not working properly, it can be a pain to get into the car if it is not addressed promptly.

However, you don’t want to waste as much money and time as possible on repairs.

To avoid wasting as much money as possible, it is important to first learn how the air conditioner works and understand the causes of malfunctions and what repairs and inspections should be done.

Causes Of Car Air Conditioning Malfunction

If you understand how your car’s air conditioning works, you can predict some of the causes of what’s going wrong.

How Does The Air Conditioning Work?

The cooling mechanism of a car air conditioner is the same as that of a home air conditioner. Refrigerant is circulated in the air conditioning system and cools the interior of the car using the principle of heat loss as the liquid evaporates.

Do you remember the near-miss when you disinfect with alcohol before an injection? When alcohol evaporates, it removes heat from its surroundings, which is why you feel cold. The principle of air conditioners is the same as this, which is called “heat-of-vaporization cooling.

Refrigerant, which is a gas at room temperature, becomes a liquid using a compressor and circulates to function as cooling. In a car, the compressor uses engine power.

The reason why gasoline consumption decreases quickly when cooling is turned on is because the compressor uses engine power, which consumes gasoline. The principle of car cooling is described above.

Next, let’s look at the possible causes of poor cooling.

Cause #1: Compressor

The first possible cause of poor car cooling is the condition of the compressor. The compressor itself is robust and rarely fails.

However, it is possible that the electromagnetic clutch, which transfers engine power to the compressor via a belt, may fail. This is not uncommon for this to cause the cooling system to malfunction.

When air conditioning is turned on, power flows to the electromagnets and the electromagnetic clutch transfers engine power to the compressor.

Therefore, if the electromagnetic clutch goes bad, engine power is not transmitted to the compressor. Naturally, the compressor will not turn, and cooling will not work.

Cause #2: Insufficient Air Conditioning Gas

In quite a few cases, cooling malfunctions are caused by insufficient air conditioning gas. The use of air conditioning itself does not reduce the amount of gas.

However, the gas may leak from a small gap in the air conditioner gas piping joints due to vehicle vibration, causing the gas to decrease little by little.

This slight decrease accumulates and results in a gas shortage, making it difficult for the air conditioner to cool down.

If the cause of the malfunction is a lack of air conditioner gas due to natural decrease, the function can be restored by replenishing the gas.

Cause #3: Air Conditioner Gas Is Leaking

Air conditioner gas in a sealed condition basically does not leak. However, air conditioner gas can leak from various parts due to damage to parts caused by aging and deterioration.

In this case, the leakage cannot be stopped unless the leakage point is identified and the part is replaced.

Causes Of Car Heating Malfunction

Next, let’s understand the causes of car heating malfunctions.

How Does The Car Heating System Work?

The heating function of a car uses “engine heat” generated by the engine’s fuel combustion, so the interior of the car does not get warm immediately after the engine is started.

The heat generated by the engine is cooled by the coolant. When wind blows on the coolant, warm air is generated and sent into the car to work as heating. Since the engine heat is used for heating, the car heating system can be used as long as the car is running.

Therefore, gasoline is not used separately for heating, and fuel economy is not reduced by the use of heating. However, pressing the A/C button will work the compressor, which will affect fuel economy.

To remove fogging inside the car in winter, it is effective to run the compressor and dehumidify the car. During heating, it is advisable to use the A/C button only when you want to remove fogging from the interior of the car in order to improve fuel efficiency.

The principles of car heating are described above. Next, let’s look at possible causes of heating malfunction.

Cause #1: Thermostat Failure

The most common cause of heat failure is the failure of the thermostat, which regulates the temperature of the coolant.

The thermostat is a component with a valve that seals off the path of the coolant in order to heat the engine quickly. When the temperature rises, the valve opens, allowing coolant to circulate through the engine’s cooling lines and regulate the water temperature.

If this valve does not close properly, the coolant temperature will not rise sufficiently and the heating system will not function properly.

Cause #2: Poor Coolant

As explained above, the car heating system uses coolant, which cools the engine, to create warm air.

If the coolant is insufficient, leaking, or clogged for some reason, the heating system will not work well. If left unchecked, the engine may even be affected by overheating. If this happens, the repair cost will be high, so be careful.

Where Can I Get Cooling And Heating Repairs?

We have explained how cooling and heating work and the typical causes of malfunctions. Next, let’s examine where you should bring your car for repair when you identify a malfunction.

The cost of car repairs varies depending on where you bring your car in. There are also differences in their specialties. It is important to understand the characteristics of each.

Maintenance Shops

If there is a maintenance shop with which you usually have a relationship for car inspections and checkups, it is a good idea to ask them to do so.

If the shop is privately owned or small, you can expect a discount depending on the nature of the relationship.

If the shop has high-level mechanics on staff, you can be assured of their technical skills. Repair costs will most likely be lower than at a dealership.


If the vehicle is under manufacturer or dealer warranty, it may be repaired free of charge. Otherwise, be aware that dealer repair costs are generally higher than those of other vendors.

Also, dealers are not good at repairing electrical systems such as air conditioners, and many dealers outsource the actual repair work.

Electrical Service Providers

This is a method of requesting electrical service from a company that specializes in electrical parts. In most cases, they are cheaper than dealers. Since they specialize in electrical parts, you can trust their technical skills.

Car Accessory Stores

Although there are differences among stores, many of them are relatively inexpensive, so it is a good idea to check the cost. However, if the work is complicated, they may not be able to handle it.

Where To Repair And How To Inspect When Cooling System Malfunctions

Review the different repair areas and specific inspection procedures for each symptom of a cooling system failure.

Check For Gas Leaks And Fill

If air is coming out but not cooling, it is suspected that the air conditioning is not working. The air is being blown and the interior of the car is not cooled.

If this symptom is present, the most likely cause is a lack of leak of air conditioning gas. In the case of a car, the air conditioning gas inside the air conditioner circulates to create cool air, so if there is a problem with the gas, cold air will not be produced.

Since the inside of an air conditioner is airtight, gas leakage is basically impossible. However, over time, a very small amount of gas may continue to leak due to vibration or other factors, resulting in a gas shortage.

There may also be a problem with airtightness due to cracks in the joints caused by age-related deterioration of the vehicle.

Compressor Repair

If there is no problem with the air conditioning gas, the cause of the lack of cooling may be a compressor failure. Normally, you will hear a click when you turn on the air conditioner switch, but if you do not hear this sound, you should suspect a compressor failure.

If there is a defect or damage inside the compressor, noise may also be heard from near the engine. If left unchecked, there is a risk of extensive repairs. It is difficult to identify the compressor as the cause of the malfunction unless you are a specialist.

If you notice silence when the air conditioner switch is turned on or unusual noise near the engine, have the compressor checked at a dealer or maintenance shop.

Check And Repair The Fan Motor

If no air comes out when the air conditioning is turned on, it is possible that the fan motor that produces the airflow is malfunctioning. This motor itself may be faulty and needs to be replaced depending on how deteriorated it is.

Inspection And Replacement Of Filters

When there is an unpleasant odor coming from the air conditioner, there is a possibility that the air conditioner filter is moldy or clogged with dust and debris.

Air conditioning is not necessary during pleasant seasons such as spring and fall. In fact, mold growth is caused by this “non-use” of the air conditioner.

If a car’s air conditioner is not used for a period of time, air does not circulate inside the car, and mold is more likely to occur. Turn on the air conditioner once a week or so to allow air circulation inside to prevent mold.

It is also important to clean and replace the air conditioner filter. As for replacing filters, DIY is possible, so we recommend doing it yourself.

Where To Repair And How To Inspect When Heating System Malfunctions

Next, we will review the areas to be repaired and how to inspect them in case the heating system stops working.

If the coolant or thermostat malfunction is left unchecked because “heating is not necessary (at the moment)”, there is a risk that the engine will be affected by overheating, so please take appropriate measures as soon as you feel a malfunction.

Coolant Replacement

In a car, coolant circulates through the engine and uses the heat taken away when cooling the engine for heating, so if there is not enough coolant, the heating system will not work properly. In this case, replenishing or replacing the coolant is OK.

Check, Repair, Or Replace The Thermostat

If there is no problem with the amount of coolant, the thermostat is the likely cause of the heating malfunction. The thermostat is the part that regulates the temperature of the coolant.

If heating does not work or becomes too hot, suspect a thermostat failure and repair or replace it.

Inspect And Disassemble The Radiator

The radiator is a part that cools the coolant that circulates in the engine and stores heat with the running wind. Its interior is filled with coolant, and coolant circulates constantly while the car is running to cool the engine.

If you notice heating problems, check to see if the coolant in the radiator reservoir tank is between “FULL” and “LOW”. If the coolant is decreasing rapidly, coolant may be leaking from a hose or other source.

If this is the case, have a professional inspect and repair the unit.

Inspection And Repair Of Fan Motor

If airflow does not come out or strange noises are heard when the heating is turned on, the fan motor may be malfunctioning. Fan motors deteriorate over time and will need to be replaced depending on how long they have been in use.

Cost And Time For Car Air Conditioning Repair

The above is how to locate the malfunctioning part of the air conditioner when it is malfunctioning. Air conditioning repair requires expertise, specialized tools and safety measures because of the handling of gas and cooling water.

Filter replacement can be done as a DIY project, but other than that, doing it yourself can be risky. Here is some information on the approximate cost of hiring a contractor.

Please keep in mind that costs vary considerably depending on the part to be repaired.

Air Conditioning Repair Prices

The cost varies depending on the cause and the nature of the repair.

Caused By Insufficient Air Conditioning gas

It costs between $100 and $300.

Caused By Air Conditioner Gas Leakage

If the leakage is caused by cracks or deterioration, simply replenishing the gas will not solve the problem. It is necessary to repair the gas leak. Depending on the location of the leak, the cost will be in the range of $550 and $1,600.

The compressor Needs To Be Repaired

Compressor failure is difficult to identify without a specialist and is often determined by bringing it in for repair. The cost of replacing a compressor is somewhat expensive at $800-$1,100.

If it coincides with the time to replace the car, it may be a good idea to compare whether to replace it or buy a new one.

Fan Motor Needs To Be Replaced

It will cost about $300 to $600.

Cost And Time For Car heating Repair

Heating repair requires replacement of thermostat and coolant. The fan motor that has deteriorated over time will also need to be replaced.

This is a painful expense, but if these are malfunctioning, the engine could overheat and cause serious problems. Repair them as soon as possible.

Thermostat Repair

This component plays an important role in addition to air conditioning. If it malfunctions, the replacement cost should be around $200.

Coolant Replacement

The cost of replacing coolant is between $100 and $200.

Fan Motor Replacement

Be prepared to pay around $400.

Time Required For Repair

It depends on the repair area. In most cases, it takes only a few hours to refill the air conditioner gas and cooling water.

If the repair/replacement is longer than that, it may take from 3 days to a week. In some cases, parts are not in stock and have to be ordered, which can take longer than expected.

Are Repairs More Expensive If The Car Is Old?

The cost of each repair is not particularly expensive when viewed in isolation. Many people will consider repairing the car and continuing to drive it.

However, if the car itself is old, the reality is that it is very unlikely that you will basically get any money for it when you buy a used car. It is not very cost-effective to spend money to repair a car that has little or no market value.

In the case of older cars, there is a great possibility that even after repairs are made, the car will continue to have problems afterwards. If such a situation persists, repairs will end up being very expensive.

It is recommended that repairs be done in consultation with the market value of the car.

Filter Maintenance Is Also Important

The filter of a car’s air conditioner is a dependable device that prevents dust and pollen from entering the car from the outside.

However, if you notice an unpleasant odor coming from the air from the air conditioner, you may suspect that the filter is dirty. Even if you don’t smell it, the filter is likely to be dirty.

Regular cleaning and replacement of the filter will free you from this odor and reduce the growth of mold and bacteria. Also, just like home air conditioners, car air conditioners “work” differently depending on filter maintenance, so be sure to maintain them well.

Many manufacturers recommend changing the filter once a year, so use this as a guideline for replacement.

Air Conditioner Filters Can Be Replaced By Yourself

In fact, you can replace the filter by yourself. In most cases, if your car model has an air conditioner filter located behind the passenger glove box, you can easily replace it.

How To Replace The Air Conditioner Filter In A Car

Specific replacement procedures are explained below.

1: Purchase An Air Conditioner Filter

Air conditioner filters can be purchased at car accessory stores, dealers, or online. The cost is about 1,500-5,000 yen. Check the model of car to which the product is compatible before purchasing.

Even for the same car model, the compatible filter may differ depending on the year and model.

The year of the car is indicated in the “first year of registration” on the vehicle registration certificate, and the model is also indicated in the “model” column of the vehicle registration certificate.

2: Remove The Glove Box

Open the glove box lid and remove the adjuster where it is hooked. After removing the adjuster, pull out the glove box as it is.

3: Pull Out The Air Conditioner Filter In Use

The air conditioner filter is located in front of where the glove box was removed. Remove the filter cover and pull out the filter inside.

4: Set A New Air Conditioner Filter

Set the new filter in place, making sure it is facing up and down. Put the cover on and put the glove box back on in the reverse order of when it was removed.

If your car’s owner’s manual contains information on replacing the filter, it is recommended that you read it carefully.


In most cases, the cause of air conditioning malfunction in a car is the compressor or air conditioner gas for cooling or the thermostat or coolant for heating.

If repair is necessary, it is possible to do it by yourself, but it is recommended to ask a contractor because expertise and specialized tools are required depending on the situation.