Why Is AC Not Working In Car : Causes & Fixes


AC not working is the most common problem with the decreasing age of the car. The air conditioner is one of the most useful parts of the car and serves to optimize the climate in the cabin.

There are also many different parts used in a car’s air conditioning unit. Parts that have different functions. Car air conditioner systems operate based on engine power and an electric DC power supply.

But sometimes some kind of fault occurs in the AC system of the car, due to which the AC in the car stops working. Through this article, we will learn in detail about AC not working in cars.

Why is AC Not Working in Car : Causes

The most common reasons for AC not working in car could be AC compressor failure, a clogged filter, serpentine belt breakage, refrigerant leaking or broken AC pipe, a faulty AC evaporator coil, a bad blower fan motor, or other electrical problems. In many cases, the air conditioner may simply need to be recharged with refrigerant.

Let us understand in detail the reasons for AC not working in cars so that you can understand the problems related to AC.

1. Leaking of Refrigerant

As you may know, there is refrigerant gas in the car’s AC to run and cool it. Due to which the AC compressor of the vehicle compresses the gas and makes cooling. But sometimes refrigerant leakage occurs in the air conditioner unit of the car.

This slowly ends up leaking out the cooling refrigerant. This can be one of the main reasons for the AC not working in the car. For this, first of all, you have to find out the leakage and correct it by applying pressure through the compressor in the AC unit of the car.

2. Clogged or Leaking AC Evaporator

leak evaporator

The evaporator coil is one of the main components for the smooth operation of the vehicle’s air conditioning system. Without it, the air conditioning system of the car cannot function.

Sometimes the AC cooling coil leaks due to not cleaning the coil for a long time or hitting something. Where AC refrigerant leaks, which can be one of the main reasons why a car’s air conditioning system is not working.

In many cases, the cooling coil of the air conditioner gets clogged due to a lack of cleanliness. Due to this, cooling cannot come from the blower of the air conditioner. To troubleshoot this problem, you will need to have this expert mechanic diagnose your air conditioner system.

If the cooling coil of the air conditioner system is leaking. So you can replace it with a new cooling coil. And if the cooling coil is clogged, get it cleaned.

3. AC Condenser or Pipes Leaking


In the car’s air conditioning system, the AC condenser is installed at the front. This AC condenser is connected to the air conditioner unit through pipes.

The AC condenser cools the back pressure created by the compressor. But sometimes, for some reason, there is a fine leak in the AC condenser or any pipe.

Due to this, the AC refrigerant ends up leaking. Due to this, the air conditioning system of the vehicle may not work. This can also be one of the main reasons why the AC is not working in the car.

4. Blown Fuse


The most important part of any vehicle’s air conditioning system is the AC compressor, which is driven by engine power. But when there is no need to run the AC, a magnetic clutch is used to switch off the compressor.

After the power supply comes, the compressor flywheel sticks to the pulley through a magnet, due to which the AC compressor starts working. To make magnets in the AC compressor, 12 V DC current is supplied from the vehicle’s electric unit.

But sometimes, for some reason, the AC compressor fuse blows. This results in no power being supplied to the magnets for the clutch of the compressor and the AC compressor not turning on. This can also be one of the main reasons for not driving like this in the car.

5. Magnetic Coil Failure

brunt ac clutch coil

There is a magnet coil inside the AC compressor, which works on a 12 V DC power supply. When the vehicle’s AC is turned on, the magnet coil of the compressor connects to the clutch pulley of the compressor, and the AC compressor rotates with the engine power through the magneto force.

When the AC compressor stops, the power supply to the compressor magnet coil stops, due to which the magnet coil loses its magnetic power. Due to this, the clutch of the compressor gets separated from the pulley being rotated by the engine, and the AC compressor stops working. Stops doing it.

But sometimes the AC compressor magnet coil gets damaged due to various reasons. This can also be one of the main reasons for the AC not working in the car.

6. AC Compressor Failure

car ac compressor

Aluminum pistons are fitted in the AC compressor of any vehicle. When the AC is switched on, the pistons pressurize the refrigerant. Compressor oil is added to lubricate these pistons.

So that the piston of the AC compressor can work properly. But sometimes, due to overheating of the AC compressor or damage to the seals or gaskets, the compressor leaks oil and refrigerant.

Due to which the pistons of the compressor get damaged due to dry running. Due to this, the AC compressor of the car does not work, and with this, many times the bearing of the AC compressor breaks, due to which the AC compressor can get stuck. This can also be a reason for the AC not working in the car.

7. Wiring Issues

To run the AC compressor of any vehicle, 12 volt DC current is supplied from the electronics unit there. so that the clutch of the AC compressor works.

But sometimes, due to some reason, the power supply wire gets cut or gets burned. So that the power supply is not available in the AC compressor, and the AC compressor cannot start.

8. Serpentine Belt Break


A vehicle’s AC compressor is driven by a belt driven by engine power. This causes the piston of the air conditioner compressor to create high pressure on the refrigerant.

The air conditioner compressor spins the refrigerant at high pressure, which releases cooling. But many times the AC compressor serpentine belt breaks down due to getting too old or overheating. Due to this, the AC compressor installed in the car does not turn on.

9. Engine Overheating


Whenever the car engine’s normal temperature is ’95 degrees to 98 degrees, But sometimes, due to some reason, the temperature of the engine becomes higher than normal, causing the engine to start overheating. The coolant temperature sensor then sends a high-temperature signal to the ECU.

Thereby, the ECU turns off the power supply to the model AC compressor, and the AC compressor turns off. Therefore, this can also be one of the main reasons for the AC not working in the car. So always keep the temperature of your car normal.

10. Faulty AC Control Panel


Inside any vehicle, the AC control panel is installed on the dashboard in the cabin. From here, the user can manage all the functions of the air conditioner, and through this panel, the power supply of the AC compressor is managed.

But this panel can get old or defective due to some other reason, due to which the functions and power supply of the vehicle’s air conditioner can be disrupted. This can be one of the reasons why the one in the car is not working.

11. Bad Power Relay

Direct power can be provided to make the AC compressor run smoothly. because the AC compressor is controlled by an ECU module, for which power is supplied through a relay.

But many times, the AC compressor relay gets burned and damaged over time. Due to this, the AC compressor of your car may not start in that situation.

How To Fix AC Not Working In The Car?

  • Check the thermostat: If the AC is not working in the car, make sure the thermostat is set lower than the current cabin temperature.
  • Inspect fuses: Check the fuses related to the AC system. If the fuse is blown, replace it with a new fuse of the same amperage.
  • Check the refrigerant level: Since a low refrigerant level can also interfere with the functioning of the AC system, check the refrigerant level using a pressure gauge. If the level is low, recharge the system with the correct amount of refrigerant.
  • Check the compressor clutch: With the engine running and the AC on, check if the compressor clutch is working properly. If not, there may be a problem with the clutch or electromagnetic coil, so get it properly repaired or replaced.
  • Check for refrigerant leaks: Oil or refrigerant leaks around AC components may result in oily residue or green stains. Fix such leaks.
  • Inspect the condenser: Clean out any dirt or debris that may be blocking air flow through the condenser. Many times, the condenser becomes broken or cracked, which requires repair or replacement.
  • Inspect the cooling fan: Make sure the radiator and condenser fans are working properly. If they are not working, it may cause inadequate cooling of the refrigerant, causing you to feel hot air even when the AC is running.
  • Check the cabin air filter: A clogged or dirty cabin air filter can restrict airflow. Replace the filter if it is dirty or clogged.
  • Check the blower motor: Also, check that the blower motor is working. If air is not coming from the vent, the blower motor is defective; repair or replace it.
  • Check the AC controls panel: Check the AC control panel and buttons. If the control buttons are unresponsive, there may be a problem with the control unit, which may need repair or replacement.


Q. How To Fix AC in Car Not Blowing Cold Air?

If your car’s AC is not working, then to fix it, you must first investigate the reasons, and after finding out the reasons, you should work to fix it. Car air conditioning repair should be done by a professional technician only.

Because the refrigerant flows in it at high pressure. Without experience, there may be a problem with refrigerant leakage, and your car’s AC may stop again.

Q. How to Recharge Your Car AC?

  •  Activate the air conditioning in your vehicle.
  •  Check to see if the AC compressor is on.
  •  Check the pressure.
  •  Attach the kit’s charging pipe.
  •  restart the car and keep an eye on the gauge
  •  Connect the recharge hose to the refrigerant can.
  •  Check the temperature inside the vehicle once again.
  • Your AC has been successfully recharged.


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