Car AC Goes in And Out: Fixing the Intermittent Air Conditioning Issue

Car AC going in and out can indicate a problem with the compressor or electrical system. When the AC compressor cycles on and off frequently, it can be caused by low refrigerant levels, a faulty pressure switch, or issues with the electrical connections.

These issues need to be addressed to ensure your vehicle’s AC system is functioning properly and providing a consistent cooling effect. A functioning car air conditioning (AC) system is crucial for a comfortable driving experience, especially during hot summer months.

However, it can be frustrating when your car AC starts fluctuating, going in and out intermittently. This issue not only affects the comfort level inside your vehicle but may also indicate an underlying problem with the AC system. We will explore the possible reasons why your car AC goes in and out and discuss some potential solutions to help you troubleshoot the issue effectively.

By identifying the root cause and taking appropriate measures, you can restore the cooling performance of your car’s AC system and enjoy a comfortable ride without any interruptions.

What Causes The Car Ac To Go In And Out?

A fluctuating car AC can be caused by issues with the compressor clutch, low refrigerant levels, or a malfunctioning pressure switch.

Car AC problems can be frustrating, especially when the air flow seems to go in and out sporadically. Understanding what causes these erratic behaviors can help you diagnose and resolve the issue efficiently.

In this section, we will explore the common culprits behind a car AC that goes in and out, including loose electrical connections, faulty compressor clutch, low refrigerant levels, and a clogged evaporator coil.

Loose Electrical Connections:

  • Loose electrical connections can disrupt the flow of power to the car AC system, causing it to turn on and off intermittently.
  • Loose wiring or connectors can lead to a poor connection, resulting in the AC cycling on and off unexpectedly.
  • Additionally, corrosion on the electrical contacts can also interfere with the proper functioning of the AC system.

Faulty Compressor Clutch:

  • The compressor clutch is responsible for engaging and disengaging the compressor, which is essential for cooling the air.
  • A faulty compressor clutch can cause the AC to cycle on and off as it fails to engage or disengage properly.
  • Common signs of a faulty compressor clutch include unusual noises, such as grinding or clicking, and reduced cooling efficiency.

Low Refrigerant Levels:

  • Insufficient refrigerant levels can cause the AC system to cycle on and off in an attempt to regulate the temperature within the vehicle.
  • Refrigerant plays a crucial role in absorbing heat and keeping the air inside the car cool.
  • A leak in the AC system or improper refrigerant recharge can result in low refrigerant levels and contribute to the erratic AC behavior.

Clogged Evaporator Coil:

  • The evaporator coil is responsible for cooling the air that enters the car’s cabin.
  • Over time, dust, debris, and moisture can accumulate on the evaporator coil, leading to clogs that hinder its function.
  • A clogged evaporator coil can cause the AC to cycle on and off as it struggles to cool the air effectively.

When your car AC goes in and out, it could be due to various factors, including loose electrical connections, a faulty compressor clutch, low refrigerant levels, or a clogged evaporator coil. Identifying the root cause of the problem is vital to ensure proper functioning of your car’s AC system.

By addressing these issues promptly, you can enjoy a consistently cool and comfortable ride.

Troubleshooting And Fixing The Issue

Experiencing issues with your car’s AC going in and out can be frustrating, especially during hot summer months. However, before you rush to the mechanic, there are a few troubleshooting steps you can try yourself to potentially resolve the problem.

By following these steps, you might be able to identify and fix the issue, saving time and money in the process.

Step 1: Checking The Electrical Connections

To begin troubleshooting your car’s AC problem, start by inspecting the electrical connections. Loose or faulty connections can cause intermittent cooling. Here’s what you need to do:

  • Inspect the Wiring Harness: Carefully examine the wiring harness that connects to the AC compressor. Look for any signs of damage such as frayed wires or loose connections.
  • Tightening Loose Connections: If you find any loose connections, use a wrench or socket set to secure them properly. Make sure all connections are tightened securely, as loose connections can disrupt the AC system’s electrical flow.

Step 2: Testing The Compressor Clutch

Next, you’ll want to test the compressor clutch. A faulty or malfunctioning clutch can cause the AC to cycle on and off. Follow these steps to check the compressor clutch:

  • Using a Multimeter to Check for Continuity: Set your multimeter to the continuity or ohms setting and touch the leads to the compressor clutch connector. If the multimeter shows no continuity, it indicates a faulty clutch that needs to be replaced.
  • Replacing a Faulty Compressor Clutch: If the test reveals a faulty compressor clutch, you’ll need to replace it. Consult your vehicle’s manual or seek professional help to ensure the correct replacement and installation.

Step 3: Checking The Refrigerant Levels

Keeping an eye on your AC system’s refrigerant levels is crucial. Low refrigerant levels can cause the AC to cycle on and off. Here’s how to check the refrigerant levels:

  • Using a Pressure Gauge: Attach a pressure gauge to the low side port of your AC system. Start the engine and turn the AC to the maximum cool setting. The pressure gauge should display the appropriate range for your vehicle. If the pressure is lower than it should be, it indicates a refrigerant leak.
  • Recharging the System: If the refrigerant levels are low, you’ll need to recharge the AC system. Visit a professional mechanic or automotive store to replenish the refrigerant to the recommended levels.

Step 4: Cleaning The Evaporator Coil

Another potential cause for your car AC going in and out could be a dirty evaporator coil. Dirt and debris can hinder the proper functioning of the coil, leading to intermittent cooling. Follow these steps to clean the evaporator coil:

  • Removing Debris and Dirt: Open the hood of your car and locate the evaporator coil. Carefully remove any visible debris or dirt using a soft brush or compressed air. Ensure that there is no blockage hindering the coil’s airflow.
  • Using a Coil Cleaner: Apply a coil cleaner designed for automotive cooling systems to thoroughly clean the evaporator coil. Be sure to follow the instructions provided with the cleaner to ensure effective cleaning.

By following these troubleshooting steps, you may be able to identify and fix the issue causing your car’s AC to go in and out.

However, if the problem persists or you are unsure about any step, it is advisable to seek professional assistance to avoid further damage to your vehicle’s AC system.

Preventive Maintenance To Avoid Intermittent Ac Issues

Regular preventive maintenance is essential to avoid intermittent issues with your car’s AC. By servicing your AC system regularly, you can ensure that it operates smoothly, providing reliable cooling and avoiding any frustrating on-off cycles. Stay cool and comfortable by taking care of your AC with preventive maintenance.

Car AC systems that go in and out can be frustrating and inconvenient, especially during hot summer months. To avoid dealing with intermittent AC issues, it is crucial to perform preventive maintenance regularly.

By following a few simple steps, you can ensure that your car’s AC system runs smoothly and keeps you cool on your travels.

Regular Ac System Inspections

  • Schedule regular inspections for your car’s AC system to identify any potential issues early on.
  • This will help prevent sudden breakdowns and expensive repairs.
  • Inspections should be carried out by a qualified technician who can assess various components for wear and tear.

Cleaning Or Replacing Air Filters

  • Dirty or clogged air filters can restrict airflow and put strain on your AC system.
  • Regularly clean or replace the air filters to maintain proper airflow and prevent intermittent AC issues.
  • Refer to your car’s manual for guidance on how often the filters should be cleaned or replaced.

Checking The Condenser For Debris

  • A dirty or blocked condenser can hinder the cooling process and cause the AC system to cycle on and off.
  • Inspect the condenser regularly and remove any debris, such as leaves, dust, or insects.
  • Consider using a soft brush or compressed air to gently clean the condenser coils.

Keeping The Car In Proper Shade Or Garage

  • Parking your car in direct sunlight can increase the temperature inside, making it harder for the AC system to cool the car efficiently.
  • Whenever possible, park your car in a shaded area or in a garage to reduce the strain on the AC system.
  • This will help prevent the AC from going in and out and maintain a comfortable temperature inside your vehicle.

Remember, preventive maintenance is key to avoiding intermittent AC issues in your car. By scheduling regular inspections, cleaning or replacing air filters, checking the condenser for debris, and parking your car in a proper shade or garage, you can ensure that your AC system functions optimally.

Stay cool and enjoy your drive without the frustration of a malfunctioning AC!

When To Seek Professional Help

If your car AC keeps turning on and off, it’s best to seek professional help. Find a skilled technician to diagnose and fix the issue for optimal comfort during your drives.

Complex Electrical Issues

Sometimes, the culprit behind your car AC going in and out is complex electrical issues. Here are the signs and symptoms to watch out for:

  • Intermittent cooling: Your car AC may work fine for a while, then suddenly stop cooling the air.
  • Uneven cooling: The cool air might blow in certain areas of the vehicle but not the others.
  • Strange noises: You may hear unusual sounds, such as buzzing or clicking, when the AC is on.
  • Dashboard warning lights: If your AC system experiences electrical malfunctions, it may trigger warning lights on your dashboard.

When it comes to complex electrical issues, it’s crucial to seek professional help. Here’s why:

  • Expert diagnosis: Professionals have the necessary knowledge and tools to accurately diagnose electrical problems in car AC systems.
  • Safety: Dealing with electrical components requires expertise to avoid potential hazards, and professionals are trained to handle such situations.
  • Proper repairs: Professionals can perform the necessary repairs or replacements to ensure your car AC functions optimally, preventing further issues down the road.

Severe Refrigerant Leaks

Another reason why your car AC may go in and out is severe refrigerant leaks. Keep an eye out for the following signs:

  • Warm air blowing: Instead of cool air, your car AC might blow warm or hot air.
  • Frequent cycling: The AC compressor may continuously turn on and off, resulting in inconsistent cooling.
  • Refrigerant odor: If you notice a sweet or pungent smell coming from the AC vents, it may indicate a refrigerant leak.
  • Noticeable leaks: Look for any visible signs of refrigerant leakage under your vehicle.

When faced with severe refrigerant leaks, it’s essential to seek professional assistance. Here’s how they can help:

  • Expert detection: Professionals can identify the exact location of the leak using specialized equipment.
  • Proper repairs: They can repair the leaks and recharge your car’s refrigerant to the manufacturer’s specifications.
  • Environmental responsibility: Professionals ensure that any leaked refrigerant is safely collected and disposed of, following environmental regulations.

Hvac System Malfunction

A malfunctioning HVAC system can also cause your car AC to go in and out unexpectedly. Here are the indications that you may be dealing with this issue:

  • Inconsistent fan speed: The fan speed may fluctuate or operate erratically.
  • Poor airflow: You may experience reduced airflow from the vents, leading to inadequate cooling.
  • Temperature control problems: Inability to maintain the desired temperature in the cabin despite adjusting the controls.
  • Unusual smells: Foul odors like mold or mildew may emanate from the AC system.

When faced with HVAC system malfunctions, professional help is recommended due to the following reasons:

  • Technical expertise: Professionals possess the skills and knowledge to identify and resolve complicated HVAC system malfunctions.
  • Component repairs: They can repair or replace any faulty components to ensure optimal performance.
  • Enhanced comfort: Professionals can restore your car’s HVAC system to its proper functioning, allowing you to enjoy comfortable rides.

When your car AC goes in and out, it’s essential to seek professional help for complex electrical issues, severe refrigerant leaks, and HVAC system malfunctions. Professionals can diagnose the problem accurately and provide the necessary repairs to restore your car’s air conditioning system’s performance.

Don’t let a malfunctioning AC dampen your driving experience; reach out to experts who can keep you cool on the road.


A car’s air conditioning system going in and out can be a frustrating experience for anyone. However, it is important to understand the potential causes and take necessary steps to address the issue. Whether it’s a faulty compressor, low refrigerant levels, a malfunctioning fan, or an electrical problem, getting it fixed by a qualified technician is crucial.

Regular maintenance such as cleaning or replacing the air filters and checking the overall condition of the system can also prevent such problems from occurring in the first place. Remember to keep an eye on the temperature gauge and listen for any unusual noises.

Ultimately, taking care of your car’s air conditioning system will not only ensure your comfort during hot summer months but will also extend the life of the overall system. So, don’t delay in getting it checked out and enjoy a cool and refreshing ride all year round.

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