Car AC Colder When Driving – Sharing My Experience – 2024

If you’ve experienced your car’s air conditioner getting colder when driving, you’re not alone. I’ve encountered this issue myself during hot summer days, and it can indeed be bothersome.

Ac Gets Colder When Driving?

Your car air conditioning works much better when you’re actually driving because the faster the engine turns, the faster the AC compressor runs, which lets the system cool more effectively. Don’t waste time and gas by letting your car run before you go.

This article will explore why your car’s AC may only blow cold air while driving and how to fix it.

Reasons Why Your Car AC Only Blows Cold Air When Driving?

When I encountered this issue with my car’s AC, I delved into understanding why it only blew cold air while driving.

1. Leakage In AC:

A refrigerant leak is one of the most common causes of a Ac blows colder when driving. The refrigerant is responsible for absorbing heat from the air inside the car and releasing it outside. The AC system may not cool the air properly if the refrigerant is low due to a leak. To diagnose the leak in the AC:

 Leakage In AC
source:trecer products
  • To begin with, check to see if the coolant level is low. If this is the case, you’ll need to add extra liquid.
  • Second, check the compressor belt for breakage or loosening up.
  • Third, verify whether the air filter requires replacing.
  • Lastly, ensure that the compressor responsible for the air conditioner is working.

Also Read: Car AC Compressor Only Runs For A Few Seconds

2. Damaged Compressor Clutch:

The compressor clutch is responsible for engaging and disengaging the compressor when the AC is turned on and off. If the clutch is damaged, it may not engage properly, causing car ac only gets cold when driving. To diagnose the damaged compress clutch:

 Damaged Compressor Clutch
source:mechanic base
  • It would help if you first looked for a power loss when you switched on the air conditioner. The air conditioning system cannot receive the necessary power if the compressor clutch is damaged since it won’t engage properly.
  • Another indication of a bad compressor clutch is an odd noise from the air conditioner if whining or grinding sounds are prominent.
  • The compressor clutch may be broken if your air conditioner isn’t blowing cold air.

3. Clogged/Blocked Compressor Clutch:

  • First, use a multimeter to verify the clutch coil for continuity.
  • Next, make sure the pressure switch is operating correctly.
  • Lastly, check to see if the air conditioning machinery is operating correctly. A blocked filter or a shortage of refrigerant could be responsible for your system’s malfunction.

4. Faulty Expansion Valve:

Air Conditioner Gets Colder When Driving? The expansion valve is responsible for regulating the flow of refrigerant through the AC system. If faulty or stuck, it may not allow enough refrigerant to flow through the system, causing the ac blows cold only when driving.

To identify the problem with the expansion valve:

Faulty Expansion Valve
source:oards automative
  • One of the most typical signs that your expansion valve is malfunctioning is if your air conditioner isn’t cooling as well as it should.
  • You can hear hissing from your air conditioner if your expansion valve is stuck open.
  • Your air conditioner cannot work if your expansion valve is stuck tight.
  • Your air conditioner may also blow hot air due to a blockage in the expansion valve.

5. AC Wiring Issues:

Electrical issues in the AC system can also cause the AC to blow warm air. For example, a loose or damaged wire may not allow enough power to flow to the compressor or other components of the AC system. To diagnose the AC wiring issues.

AC Wiring Issues
  • Examine the insulation of the wire to check whether it has been affected.
  • Next, check the connections between the air conditioner and the electrical panel.
  • Finally, look for any sign of damage on the AC unit. You need to be able to identify and fix anything wrong with the AC wiring by using these steps.

Also Read: Car AC Only Blows Cold Air On “LO” Setting

6. Low Coolant Level:

Low coolant levels in the car’s engine can cause the AC to blow warm air. The AC system relies on the engine’s cooling system to remove heat from the refrigerant. To diagnose the low coolant level:

Low Coolant Level
  • Inspecting for leaks in the radiator is the initial step.
  • Checking the oil level in the engine is another approach to determining low coolant levels. The coolant level will likely be low if the oil level is low.
  • In the end, check the radiator’s coolant level with a hydrometer. The coolant level is likely inadequate if it is below the hydrometer’s lowest reading.

7. Faulty/Clogged Condenser Fan Not Blowing Cold Air:

Why Does My Car Ac Get Colder When I Drive? The condenser fan is responsible for blowing air across the condenser to help dissipate heat from the refrigerant. If the fan is faulty or clogged with debris, it may not be able to blow enough air to cool the refrigerant, causing ac only blows cold when driving. To diagnose a faulty or clogged condenser fan:

Faulty/Clogged Condenser Fan Not Blowing Cold Air
source:brown-daub kia
  • Initially, check to see if the fan blades are clean. If they are dirty, they might not spin properly.
  • Second, check whether the fan motor is damaged or burned out.
  • Finally, look for debris or blocking in the condenser coils.

Also Read: AC Not Working And Car Overheating

How To Fix Car AC Only Colder When Driving?

To address the issue of my car’s AC blowing colder only when driving, I explored various solutions.

1. Fixing The Refrigerant Leak:

Why Isn’t My Ac Cold In My Car? Finding and correcting the leak’s source is the first step in resolving a refrigerant leak. A professional mechanic can use a special dye or a refrigerant leak detector to identify the leak’s location. After rectifying the leak, the system may be refilled with the appropriate amount of refrigerant.

Fixing The Refrigerant Leak
source:bluedevil products

2. Replaced Damaged Clutch:

If the compressor clutch is damaged, it will need to be replaced by a professional mechanic. They will replace the old clutch with a new one.

3. Fix Clogged Compressor Clutch:

  • Using a clean towel, wipe down the compressor clutch. You might want a toothbrush or a tiny brush to remove the debris.
  • It might be essential to replace the compressor clutch if it continues to find it challenging to engage correctly.
  • You can always seek expert advice if you’re unclear on how to fix a jammed or blocked compressor clutch.
Fix Clogged Compressor Clutch
source:motor verso

4. Fix Expansion Valve:

  • Check the unit’s power supply first. Whether the power is on or off, turn it back on and make sure the expansion valve is working correctly.
  • The expansion valve may need to be replaced if the electricity is turned on, but it still fails to work.
  • To achieve this, power off the unit’s power and separate the expansion valve from it. After that, replace the old expansion valve.
  • Finally, Reconnect the electricity and confirm that the expansion valve operates correctly. If so, you may proceed.
Fix Expansion Valve

Also Read: Car Jerks When AC Is On

5. Fix AC Wiring Issues:

  • Make sure your air conditioning system’s connections are thoroughly examined. Please make sure they are tight and stable.
  • Check the wiring for damage signs. If you discover any damaged wires, replace them with new ones.
  • Regularly check your fuses, and replace them if they blow.
  • To ensure everything functions, have a professional inspect the AC system regularly.
Fix AC Wiring Issues

6. Add Coolant:

How to make car ac colder?

  • First, inspect the cooling system for leaks. You can add coolant to the system if there are no leaks. Use coolant that is suitable for the vehicle you have.
  • An expert can also flush and refill your car’s cooling system.

7. Unclogged Condenser Fan:

  • To begin, ensure that the fan blades are clean. They will not spin properly and will eventually shatter if they become blocked with dirt and dust. They are easy to clean with a soft cloth or brush.
  • Examining the fan’s bearings is yet another choice. They must be changed if they start to wear out.
  • You might need to replace the condenser fan if all else fails. Due to the excessive expense, it is generally the last option.
 Unclogged Condenser Fan

1. Is It Normal That My A.C Only Gets Cold Once I Start Driving?

A defective condenser fan may cause the air conditioning to only work when driving. These fans help lower the refrigerant’s temperature to ensure condensation, and malfunctions can impede this process.

2. Why Does My Car Ac Only Get Colder When Driving?

When your car’s AC only gets cold when driving, it’s likely due to issues with the fan system, such as dirty fins or a malfunctioning fan clutch. Low refrigerant levels can also impact cooling efficiency.

3. Why Is My Ac Cold When Driving And Warm When Idle?

Reduced airflow across the condenser when the car is idling can lead to warmer air. Since there’s no wind to help cool the condenser when stationary, the A.C may seem warmer at idle.

4. Why Does My Car Ac Get Warm When I Drive?

If you experience hot air while driving and cold air when idling, it could indicate a vacuum leak, causing the vents to switch to defrost mode. Check the fans and refrigerant levels if the issue persists.

5. Why Is My Car Ac Not Cooling When Parked?

A malfunctioning cooling fan in the condenser could be the culprit, as it helps cool down the heat from the refrigerant. If the fan is damaged or unable to run at full force, cooling efficiency may be compromised.

6. Why Does My Ac Only Get Cold When I Accelerate?

Similar to the previous scenarios, inadequate airflow through the condenser due to fan system issues or low refrigerant levels could cause the A.C to only get cold when accelerating.

7. What Is The Life Expectancy Of A Car AC Compressor?

An air compressor might explode if it is not maintained correctly. If the air compressor is not sufficiently cooled, the air within the tank might get too hot and cause an explosion.

8. How Can You Tell If Your Car’s Air Conditioner Is Low On Freon?

Signs of decreasing Freon in your car’s AC include less icy air from the vents, ice buildup around the unit, and increased cycling of the compressor.

9. Is It Possible For An Air Compressor To Explode?

If an air compressor is not maintained correctly, it can explode. The air inside the tank can become too hot if the air compressor is not adequately cooled, causing the tank to explode.

10. Why Does My Ac Stop Blowing Cold When Idle?

When idle, low refrigerant levels, clogged coils, or faulty compressor/fan clutch can cause your AC to stop blowing cold.


A car AC that only blows cold air when driving can have several underlying causes, including refrigerant leaks, a faulty compressor clutch, a clogged compressor clutch, a faulty expansion valve, AC wiring issues, low coolant levels, or a faulty/clogged condenser fan. It’s essential to have the problem diagnosed and repaired by a professional mechanic to ensure the proper function of the AC system.

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