Car AC not blowing cold air when idle can be for various causes because various components operate the car’s air conditioning system.
But, finding the causes of why car AC is not blowing cold air when idle is going to be very simple if you can diagnose faulty parts of your car cooling system.
Your car AC should blow cold air as long as the engine is running when your car is idling so that your body doesn’t sweat inside the car when it is hot outside.
The engine powers the air conditioner. Hence, you cannot run your car’s air conditioning without the engine ruining it. And cars only idle with the engine on.
So, when your car AC is not cooling when idle, your car cooling system has issues with several components of the car.
The following guide will tell you why a car air conditioner does not blow cold air when idling and what you should do when the AC is not cold at idle.
What Causes Car AC Not Blowing Cold Air When Idle
Low on refrigerant, broken or completely blocked condenser, overheated engine, debris in car air conditioning system, and worn-out condenser parts are the most common causes of car AC not blowing cold air when idle.
Here are some common causes why car AC not blowing cold air when idle:
- Broken or Blocked Condenser
- Overheated Engine
- Bad Condenser Fan
- Low on Refrigerant
- Worn-out Condenser Parts
- Debris Particles in Car AC System
1. Broken or Blocked Condenser
The car condenser of the air conditioning system cools down the refrigerant gas to blow cold air; it compresses the refrigerant.
As you might know, a car’s AC condenser placed before the radiator means the air conditioning condenser is situated in the front of the car to maintain the flow of air coming from outside as it needs to cool the refrigerant rapidly.
For the location of the AC condenser, debris, wreckage, and dirt can get into the condenser so easily that car drivers cannot even notice.
When the car condenser gets blocked or broken, it cannot cool down the refrigerant, and eventually, your car AC doesn’t blow cold air when idle. So, a blocked condenser can be a cause of why your car AC is not blowing cold air when idle.
Any of the hard wreckage can clog or break the car cooling system’s condenser. An air conditioning clogged or broken condenser won’t let the AC compressor compress hot air to cold air.
If your car’s AC condenser keeps blocked for a certain period of time, it is going to be a major cause of the AC compressor malfunctioning. So, keep your eye on the car’s AC condenser when you get a chance.
Related: Car Shakes When AC Is On
2. Overheated Engine
An overheated engine is another common cause why your AC is not cold when idling because the vehicle’s air conditioning system is connected to the engine.
The car air conditioning operates by drawing energy from the alternator, which is powered by the engine. Therefore, the engine must be operated properly to keep up the cold air blowing from the AC.
The condenser and radiator fan both keep working to cool the engine and air conditioning air. So, both fans need to work as they should.
The ideal engine temperature should be between 195 and 220 degrees. If your car engine temperature goes above, then your car AC can blow hot air when idle.
3. Bad Condenser Fan
As you know condenser is a major component of a car cooling system. The condenser fan is responsible for blowing the air through the condenser coils to convert hot, Freon gas into a cool liquid.
But, if the car air conditioning system condenser fan can’t work, the condenser can’t compress the gas to blow cold air when the car is idle.
The AC condenser fan needs to be in the right slot, and connections should not be loose to run without any difficulty.
However, when you drive your car at high speed, the condenser fan doesn’t need to cool the Freon because the Freon gets air from the outside.
And when the car is idling, the condenser fan is the only tool that can cool the Freon. So, if your car has a damaged or broken condenser fan, your car’s air conditioning is not going to blow cold air when idling.
See Also: Car Overheats When AC Is On
4. Low on Refrigerant
Refrigerant is also known as Freon, and it should be at the right level to produce cold air. The cold air that comes out from the air conditioner is the refrigerant gas.
So, when the refrigerant level is low, your car AC doesn’t blow cold air when idle. Therefore, the car air conditioning system must have sufficient refrigerant to produce cold or hot air.
A sufficient amount of refrigerant becomes more necessary when your car is idling because the compressor gives extra effort to circulate the refrigerant. Likewise, the AC compressor needs less energy to blow cold air from the air conditioning when the car is running.
Considering several causes of low Freon in air conditioning, leakage is the most common. In most cases, the refrigerant level goes low because of leakages.
You can check the refrigerant level of your car AC. The ideal Freon level should be below 30 psi on the low side, moreover below 150 psi on the high side.
Whether you need to refill the Freon in the car AC system or remove Freon from the car, both are simple tasks to do.
5. Worn-out Condenser Parts
In air conditioner systems, an essential component is a condenser; that’s why keeping it in check is always necessary.
The condenser can malfunction because of any worn or blocked, or faulty components inside it, which is another reason why a car air conditioner does not blow cold air when idling.
A condenser is combined with other parts like a condenser motor, coil, fins, tubes, relay switch, and run capacitor. The condenser won’t be able to work properly if any of those parts are not functioning.
The car condenser parts can wear out for aging; therefore, if the parts need to be replaced with new ones, then you must replace them to keep your car’s air conditioning running.
6. Debris Particles in Car AC System
The car AC system needs to be away from any foreign objects; debris can prevent the air conditioner from flowing cold air, whether the car is running or idling.
A small amount of dirt or debris particles can cause blockages in the AC compressor, and this situation causes the aircon not to be cold when the car is idle.
There are several ways debris can get into your car’s air conditioning system to make it not blow cold air. The vehicle’s air conditioning system is always located in the front part, so it is so easy to get debris and waste.
Even any strong waste can break the compressor or condenser, or radiator, which would not be a good circumstance for an air conditioner.
How To Fix A Car AC That Does Not Blow Cold Air When Idling
The fix for a car AC that does not blow cold air when idling is not very simple. You need to be certain of what causes a car AC not to cool when idle before starting to repair or replace any components of the AC system.
Follow the guide below to fix a car AC that does not blow cold air when idle:
Keep The Car’s AC Condenser Clean
If your car’s AC is not cold at idle, you should first clean your car’s AC condenser.
As you know, a blocked AC condenser won’t cool down the refrigerant gas and makes the aircon not cold when idle. By cleaning, you can remove blockages from the AC condenser.
When a car’s AC condenser stays neat and clean, the air conditioner performance will be more effective, and AC can operate optimally.
Frequent cleaning will prevent all that debris from getting stuck into the condenser. Always try to keep the condenser clean. It is the best practice to avoid this issue in your car’s ac system.
Check Condenser Parts
Your car condenser consists of various parts. The car condenser parts include the motor, fins, relay switch, and more.
The condenser operates properly when the parts are not failed or worn out. So, when your car AC is not blowing cold air, it’s necessary to inspect the parts of the condenser.
Often, car condenser parts need to be replaced instead of repaired. And some of the condenser components are relatively easy to replace, such as bad condenser relay switch, faulty motor, bad run capacitor, and other components too.
If you need to replace the condenser, it will cost you more money than just repairing it.
Replace Condenser Fan
The cooling fan is another essential part of the condenser. A broken or defective condenser fan won’t be able to transfer heat from the refrigerant, and that makes your car AC not cold at idle.
Because of the location of the condenser fan, it gets hit by many foreign objects, which is why the condenser fan can easily break and get damaged.
Test the performance of the car’s condenser fan, and replace it if it is not working effectively. The replacement cost of the condenser fan should not be more than $200 as of now.
Flush The Car AC System
As you know already, debris in the car air conditioning system is a cause of the car air conditioner not blowing cold air when idling.
And to make the car air conditioning system clean again, flushing is the best option so far. Flushing ensures that the air conditioning system is clean and contaminants free completely.
Stop Leakages In The Air Conditioning System
Any leakages in the AC system lead to the regiment level low and also bring other cooling system issues.
It’s too obvious to see the car AC not blowing cold air when idle because of leakages in the car air conditioning system.
The worn seals, hoses, and tubes of the air conditioning system are the reasons why the car AC is leaking. Ensure the AC system’s hoses and seals are connected as they should be and not creaked.
For the most part, your car AC is not blowing cold air when idle because of a bad condenser. Without a functional condenser, the car’s air conditioning is not going to blow cold air.
Therefore, when your car AC is not cold when idling, check any blockage in the condenser and ensure the condenser fan is running as it should be.
Check the refrigerant level if the AC is not cold at idle. If Freon is low, refill the refrigerant right away.
Do not overlook dirt in the car air conditioning system because any debris particles can clog AC components. Flash the AC system to increase the car’s cooling system performance.
There is no excuse for car AC not blowing cold air when idle is our vehicle’s major problem. But for ignorance, the air conditioner might cost you a couple of hundred dollars or a thousand dollars later.
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I’m Meraj Sarker. I am a Car Mechanic and a student of Automobile Restoration here in Florida, USA. I’ve been studying automotive for around 9 years now. So you can rely on my recommendation. For me, studying and getting knowledge about automobile it’s really fun and entertaining. I will help you to get solutions for your car through this website. If you need any help let me know.