Auto AC
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Beat the Heat: 5 Quick Fixes for Car AC Not Cooling in Jonesboro

Published on
June 5, 2024

It's that time of year when the hot summer sun is beating down and you desperately need your car's air conditioning system to provide some sweet relief. But then you turn it on and realize it's only blowing lukewarm air or making weird noises. A car AC not cooling can ruin your drive and leave you sweating buckets.

Don't panic yet! Many common issues can cause an AC to stop cooling properly. With some troubleshooting and repairs, you can get your car's AC back to blowing cold again. This article will go over the various reasons your car's AC may not be cooling, explain the typical causes for each one, and provide solutions to restore its cooling ability. Read on to pinpoint why your car AC is misbehaving so you can get it fixed and enjoy a frigid cabin once more!

Check Refrigerant Levels  

One of the most common reasons for poor AC cooling is low refrigerant levels. Refrigerant is the substance that enables the AC system to produce cold air. When refrigerant levels drop due to leaks or regular use over time, it prevents the AC from providing proper cooling.

Signs that your car's AC may have low refrigerant levels include weak airflow from the vents, warm air instead of cold, and the system taking a long time to cool down the interior. You may also notice the AC works well at first but gradually gets warmer.

Checking the refrigerant levels and recharging the AC system if needed is crucial for restoring cooling function. While DIY AC recharging kits are available, it's highly recommended to have a professional mechanic handle refrigerant recharging. They have the tools and expertise to safely add refrigerant to the precise levels your AC system requires.

Attempting to recharge the AC system without proper training could lead to overfilling, which can damage the compressor. Most mechanics use a refrigerant identifier tool to check the type and levels before adding more. Once recharged properly, the AC should blow cold air again. Regular AC system inspections can help avoid low refrigerant and keep your car cool all summer.

AC Compressor Issues 

The AC compressor is responsible for circulating refrigerant throughout the air conditioning system. If it is faulty or failing, it can prevent the system from providing adequate cooling.

Some signs of a bad AC compressor include:

  • Lack of cold air blowing when the AC is turned on
  • Intermittent cooling performance 
  • Unusual noises coming from the compressor
  • Higher than normal system pressures

To diagnose compressor problems, a technician will likely conduct a visual inspection and use AC pressure gauges. The gauges measure high and low side system pressures to determine if they are in the normal range. Abnormal readings can indicate issues with the compressor or other AC components.

If the compressor is confirmed to be malfunctioning, it will need to be replaced by a professional. While the compressor itself may not be too expensive, labor costs can be significant for this repair. Preventative maintenance is recommended to maximize the compressor's lifespan.

AC Condenser Problems

The AC condenser is responsible for expelling heat from the refrigerant as it circulates through the system. If the condenser is blocked or damaged, it won't be able to cool the refrigerant efficiently. This causes the refrigerant to remain hot, preventing the evaporator from absorbing heat from inside the cabin.

Some common condenser issues include:

  • Debris buildup on the condenser fins - Things like dirt, leaves, bugs, and other debris can block airflow through the condenser. This reduces its ability to expel heat.
  • Bent or damaged condenser fins - Fins that are bent out of shape or damaged will disrupt proper airflow. The condenser needs maximum airflow contact to work correctly.
  • Corrosion - Rust and corrosion on the condenser and fins degrades the metal over time. This reduces heat transfer efficiency.
  • Condenser fan failure - The condenser relies on airflow from the fan to cool itself. If the fan stops working, the condenser can't expel heat properly.

In many cases, cleaning the debris from the condenser fins can help improve its performance and airflow. If there is damage to the fins or fan failure, condenser replacement may be required. An AC technician can diagnose the extent of the condenser issues and recommend the necessary repairs. Properly functioning condenser components are critical for allowing the AC system to cool the interior cabin.

Evaporator Issues

The evaporator is a key component of your car's AC system, located inside the dashboard. It absorbs heat from the air inside your car to provide cooling.

Over time, the evaporator can become clogged with dirt, pollen and debris. This prevents it from absorbing heat effectively, reducing its cooling capabilities. Signs of a clogged evaporator include weak airflow from the vents and little difference in temperature between outside air and air from the vents.

If the evaporator is very dirty, the only solution may be to have it professionally flushed or replaced. An experienced AC technician can determine if cleaning is possible or if full replacement is required. They will have the proper equipment to safely clean the evaporator without damaging it. 

Replacing the evaporator can be quite expensive, so try cleaning first. But if it is too clogged, bite the bullet and install a new evaporator so your AC can work properly again. Avoid trying to clean it yourself, as the evaporator is delicate. Trust an expert AC repair shop in Jonesboro to handle evaporator issues correctly.

AC System Leaks 

One of the most common reasons an AC system stops cooling properly is a refrigerant leak. The AC system relies on refrigerant circulating in a closed loop and building up pressure. Any leaks will cause the refrigerant to escape and the pressure to drop, preventing the AC from providing cold air.

Over time, the seals and O-rings in the AC system can crack or fail, allowing small leaks to develop. The refrigerant is eventually depleted, leaving only hot air blowing through the vents. Refrigerant leaks often start out very small and gradually get worse over months or years.

The most reliable way to detect AC leaks is to have a professional perform a UV dye test. They will add fluorescent dye to the AC system, then use a UV light to spot any leaks. The dye will glow brightly at the source of the leak. A thorough inspection of all AC components should locate even minuscule leaks.

Once a leak is found, it must be repaired to stop further refrigerant loss. The damaged component such as a hose, seal or O-ring will need to be replaced. Then the system can be evacuated of air and recharged with fresh refrigerant. Proper refrigerant pressure should then be restored, allowing cold air to flow once again. Catching and repairing leaks early is key to avoiding a completely depleted AC system.

Faulty AC Controls

Electrical issues with the various AC control components like sensors, switches, and control units can also cause cooling problems. The complex AC system relies on multiple sensors and switches to activate different components like the compressor clutch, blower motor, and blend doors. If any of these develop faults or become disconnected, it can disable part or all of the AC system.

Troubleshooting electrical AC control issues requires using a wiring diagram to trace the circuits and then testing them with a multimeter. Look for opens, shorts, faulty grounds, and out-of-range sensor readings. Repair any damaged wires. If a sensor or switch tests faulty, it will likely need replacement. On modern vehicles the AC control unit is often integrated into the body control module or HVAC module, which requires programming and may need dealer replacement if it fails.

Pay attention to any AC-related warning lights on the dash as these can indicate a faulty sensor or control unit. Intermittent AC problems are often due to a loose wire or faulty electrical connection. Wiggling wiring harnesses while monitoring voltage signals and AC operation can help isolate the issue. Control problems will disable AC operation and require repair for the system to work properly.

Blower Motor or Fan Failure 

The blower motor and fan are responsible for circulating the cooled air from the AC system into the cabin. If the blower motor is faulty or the blower resistor has failed, it will prevent cooled air from properly entering the interior.

Some signs of a failing blower motor or resistor include:

  • Weak airflow or no airflow from the vents, even when the fan speed is turned up. This indicates the blower motor is not spinning at the correct speed.
  • Intermittent operation, with the blower cutting in and out randomly. Points to an issue with the motor or resistor.
  • Strange noises coming from the blower motor area under the dash when turned on. Could signal a bad bearing or electrical issue.
  • The blower only operates on certain fan speeds but not others. Typically caused by a failed blower resistor.

To diagnose, first check that the blower motor is receiving proper voltage when switched on. Use a multimeter to test for 12+ volts at the blower motor electrical connector. 

If voltage is present but the motor does not run, the windings inside the motor could be damaged and need replacement.

If voltage is very low or nonexistent, focus on the blower resistor. This component regulates voltage to the fan speeds. When it fails, voltage will not pass through properly.

Replacing a faulty blower motor or resistor will restore proper airflow and allow cooled air to circulate throughout the cabin once again.

Blocked or Dirty Cabin Air Filter 

One common reason for reduced AC performance is a blocked or dirty cabin air filter. This filter is responsible for removing dust, pollen, and other particles from the air entering your vehicle's interior.

Over time, the cabin air filter can become clogged with debris, restricting airflow through your AC system. Many automakers recommend replacing this filter every 12,000 to 15,000 miles.

If you haven't replaced the cabin air filter recently, a clogged filter could be the culprit behind your AC troubles. Replacing a dirty filter is an easy DIY project that can restore proper airflow and improve cooling.

To replace the cabin air filter, consult your owner's manual for the location under the hood or behind the glovebox. Remove the old filter and clean out any debris. Insert a new filter, making sure the airflow direction matches the arrows on the filter. Close up the housing and you're done!

Replacing a blocked cabin air filter is an inexpensive and straightforward fix that can get your AC blowing cold air once again. Be sure to replace it per the recommended maintenance schedule to maintain optimal performance.

Conclusion

Keeping your car's air conditioning system in good working order is important for comfort and safety while driving during warm weather. There are several common issues that can cause AC problems, ranging from low refrigerant levels to clogged air filters. Being aware of the possible causes can help you diagnose and resolve cooling problems more efficiently.

If you've tried basic troubleshooting steps and your AC still isn't blowing cold air, the best solution is to have your system inspected by a trusted auto mechanic. A professional can use specialized tools to test your AC components and pinpoint any leaks, blockages, or malfunctions. They can then make the necessary repairs to get your air conditioning functioning properly again.

In addition to repairs, there are some helpful maintenance steps you can take to prevent AC problems in the future:

  • Check refrigerant levels yourself periodically and have a mechanic top it off if needed. Low refrigerant is a major reason for reduced cooling.
  • Replace your cabin air filter regularly, about every 15,000 miles. A clogged filter can restrict airflow.  
  • Have your AC system inspected annually before summer to identify potential problems early.
  • When washing your car, avoid spraying water directly into the AC condenser fins to prevent damage.
  • Run your AC regularly to keep the seals lubricated. Long periods of disuse can cause the system to seize up.

With some preventative maintenance and the skill of an experienced mechanic, you can keep your car's air conditioning blowing cold air all summer long. Don't tolerate a faulty AC - identify issues promptly for a quick resolution.

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