How To Troubleshoot A Broken Car Air Conditioner
Rocco Lovetere
It can be very frustrating to have your cars AC go out on you, especially on a hot day when you need it most. Luckily there are just a few simple steps that can assist you with diagnosing your vehicle with a non-working AC. Not only will they help you diagnose the problem, but they will also help you have a better grasp on the workings of your cars AC system, resulting in a repair that is not only speedy but accurate.
Before starting any of the following steps towards diagnosis, you will want to make sure that your vehicle is on, with the engine running, with both the gear in park and the parking brake engaged. This will ensure you are also proceeding as safely as possible.
Hvac Control Module Program Needs A Reset
After disconnecting the battery, sometimes you can interrupt the HVAC control modules program that conducts a self-test to find the blend door actuators location. If this happens, the module might read inaccurate data, leading to an inaccurate temp and requiring recalibration.
If the program needs to be recalibrated, sometimes it can be reset by disconnecting the negative terminal on the battery for about 5 minutes. After this, turn the key on and do not touch any HVAC controls. Hopefully this will reset the module.
Higher Temperatures Than Normal In The Cabin
One of the first signs which is really to recognize symptoms of bad AC compressor is the AC no longer blowing as cold as it did. A damaged or failing compressor will not be able to properly regulate the refrigerant flow in the AC system, and as a result, the AC will not function properly. So you may notice that the degree inside the car increases and the airflow from the AC is hot. There are 3 possible reasons behind, first is the low level of the refrigerant, second is the leak of the refrigerant and the third is the compressor is going bad and needs to be replaced.
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Ac Clutch Not Engaging Do This Quick Check To Know Why
The AC compressor cannot pump the refrigerant if the clutch does not engage. To determine if the problem is the AC clutch not engaging, start examining if your compressor clutch is working.
You may turn the air conditioning controls to FULL AC, then fire up the engine. Check the front of the compressor clutch. If the pulley and the clutch are both spinning it shows that the clutch is engaged with the pulley correctly. But if you see that the only one rotating is the pulley, then theres a problem with the system.
Your Ac Refrigerant Needs A Recharge
The most common cause of a vehicle’s air conditioner not getting cold enough is that it needs to be recharged. You can recharge your refrigerant by yourself, but to save time and make sure the job is done correctly you should make an appointment with your local professional auto shop.
The trusted professionals atAce Auto in West Jordan, Utahcan help you recharge your car’s AC refrigerant. Give us a call at 801-447-1693 for a free quote to get you back on the road with the comfort and safety with a recharged AC blowing crisp, cool air again.
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Understanding Your Vehicle’s Ac System
The air conditioning system in your vehicle can be complex due to the location of the hoses and lines. Essentially, your vehicle’s AC system compresses and heats the refrigerant, then allowing it to decompress and condense into a liquid that causes it to rapidly lose heat. This process absorbs heat from the car’s cabin and is continuously repeated to achieve your desired temperature.
The basic concept is much easier to understand when the components are broken down, as follows:
- The compressor runs off an engine belt that squeezes or compresses the gaseous refrigerant.
- Once it has been pressurized, the condenser cools it down through a series of finned tubes where it returns to a liquid state. This liquid will then pass through a dryer or receiver that removes excess water to eliminate the risk of ice crystal formations inside the AC system.
- Next the liquid refrigerant enters the evaporator via a thermal expansion valve where it is then exposed to heat from the vehicle’s cabin. At this point the fluid boils, reducing it to a gas form once again. During this process the heat from the surrounding air is absorbed causing the evaporator coil to chill. Finally, it is redistributed throughout the cabin by the blowing fan through the vents as cool, crisp air-conditioned air.
Here are the top 3 reasons why your car may not be blowing cold air:
Common Reasons Why The Ac Clutch Doesnt Engage
There are many reasons why an AC clutch does not engage. It could be because of a blown fuse, a bad clutch coil, or an open on the wire to the clutch coil. It could also be of poor ground or a low-pressure lockout.
There are many ways for AC compressor clutches to receive power. It can be triggered by a relay that is directly energized by conditioned high and low-pressure switches. Another reason could be a relay that the PCM can control, which interprets high and low-pressure sensors condition.
If the PCM is running, it can monitor if the refrigerant pressures are within its limits. Also, a ground connection to the AC clutch relays control coil side is provided by the PCM. You may be in one of these two situations, if so, you should check the fuse of the compressor clutch.
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The Basic Principles Of Car Air Conditioning
The main goal of the vehicle A/C is to cool or lower the temperature of the surrounding air. It does this by reducing the moisture content of the air, which is lowering the relative humidity so to speak. Hot air is filled with moisture. Colder air is dryer. The air conditioning system will absorb the air inside the cabin, remove or lessen the humidity, and blow the cooler air via the air vents.
It all sounds simple, right? The main principles in a typical air conditioning system are evaporation, condensation, compression, and expansion. The main parts of an A/C are the following:
Common Reasons A Car’s Ac Isn’t Cooling
While there are a variety of reasons your car’s air conditioning might not be operating at top performance, the most common are a refrigerant leak, an electrical climate control issue, or a problem with the air conditioning compressor. Each of these can cause the AC to blow lukewarm or hot instead of cold air.
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Reason #: Electrical Issues
Electrical issues are perhaps the most difficult problem to diagnose when it comes to an A/C unit that has stopped working. First, a visual inspection of all the wiring should be done to see if any wires are broken or frayed.
If any damaged wires are found, they should be mended with electrical tape or replaced altogether. If youre unable to visually locate any electrical issues, it may be time to take your vehicle to an experienced dealer for further diagnosis.
No : Your Cooling Fans Are Broken
Just like you need blowers to push the air conditioning through the vents in your home, your car uses cooling fans to move the refrigerated air into your vehicles cabin. When theres a problem with the fans, you wont feel any air coming out of the vents.
Cooling fans can stop working properly for a number of different reasons; they might have blown fuses, an electrical short, or could have been cracked by debris from the road. Fortunately, this is fairly simple to fix; your mechanic should be able to replace it quickly and get you back on the road.
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What Causes The Car Ac To Smell Bad
In short: moisture.
Your vehicles air conditioning system does not actually create cold air; it takes heat and moisture out of the air that is outside of your car, which in turn, makes it feel much cooler than the air around you.
The coils in the AC unit work to condense the heat and moisture in the air, taking out the humidity before pushing the cooled air into your car.
As these coils are colder than the air around them, hot air flowing into the unit can create moisture pockets that surround the condensing unit in your AC system; which create small pools of water that are drained outside of the car via the drain line.
However, if moisture becomes stuck or for whatever reason cannot find its way out of the AC unit, by drainage or evaporation, the water will pool inside the unit and around the coils creating moisture inside of the AC unit.
The culprit: mold.
If your drain line is damaged or you frequently use your AC system, the unit is likely to stay damp all the time, which creates a breeding ground for mold and bacteria.
The air that passes through the evaporator and the units mold build-up will carry the foul smell inside of your car through your dash vents.
Mold is the most common culprit for causing raunchy smells to come out of your cars AC.
Odor-causing mold loves to reside in your cars AC unit because it is always moist and dark ingredients for a happy home for mold.
Car Air Conditioning Not Working: Why Its Happening And How To Fix It
When your car’s air conditioner isn’t cooling anymore or worse, blowing hot air it can make for an uncomfortable ride on a warm day. The solution could be a simple one, but it could also require a complex repair that would be risky to attempt at home.
There are two basic types of problems you can experience with your car’s air conditioning. Each one will have different symptoms, and different potential solutions. Choose your issue below to see more details.
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Is Car Ac Cooling Low Mould And Mildew Build
When we tend to keep the car AC On for a long time, small microorganisms can block the AC vents. These bacteria can block the AC vent and affect the cooling procedure. When this happens, no matter how much you try, the vents dont work properly. Its one of the reasons for which your car AC is not cooling the cabin properly.
To avoid one such threat, its better to take the car for servicing at least after 5-6 months. A periodic service not only clears the AC duct, but it also evades common dust particles and other microorganisms like bacteria and moulds to grow and propagate on a rapid scale.
Its not only a hygienic remedy but also a smart way to maintain the durability of your car Air Conditioner thereby adding longer life span to your car air cooler.
Issues In The Electrical System
If your AC is blowing hot air, the last thing you want it to stem from is an electrical issue. Why? Because tracking down where the problem is can be tough since many of the wires arent visible without dismantling the system.
Many of the AC components need electricity to function, if they arent receiving any, your AC system will likely blow warm.
While you may be able to mend any frayed or damaged wires with electrical tape, your best bet is to take it to an experienced professional.
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How To Check Whether Your Ac Clutch Is Working
Keep in mind that the compressors main function is to ensure that the refrigerant changes gas to liquid. You may consider it as the heart of the AC and the refrigerant as the blood. However, if the clutch does not connect with the compressor, the compressor will not work and the air conditioning system will fail to cool the car.
Try checking if the clutch is in good condition by applying these steps:
- Turn the AC controls to maximum air conditioning.
- Start the car engine.
- Look closely and observe the front part of your clutch.
- Make sure that the clutch and the pulley is spinning simultaneously.
- If the only rotating part is the pulley, then the clutch fails to run.
Here is a useful tip: If youre not confident to do the examination yourself, it is best to work with a car expert. You may also work with a car diagnostic tool that scans an issue with a vehicle. Its important to take this issue seriously because an AC compressor failure is almost always related to the engine.
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Why Is My Car Air
Clancy Harrip
Summer in Australia can be brutal and when your cars air conditioning unit is blowing hot air, it can be frustrating and uncomfortable.
However, not having working A/C is also a safety issue – being inside a hot car during summer can spike your body temperature to a dangerous level.
So, if your car is experiencing A/C issues you should take immediate steps to fix it, not only for your own comfort but, more importantly, for your safety.
Here are six common reasons why your cars air conditioning may not be working.
Broken Ac Expansion Valve
Compared to the evaporator coil, the AC expansion valve is cheaper to replace. It is also a simple replacement to do. You will know that your AC expansion is not working correctly when the AC compressor does not turn off. It may be because the vents are covered with frost. Consequently, the vents may be giving off heat.
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No : Theres A Problem With The Compressor
Your air conditioning relies on a compressor to keep the air moving, but if the compressor isnt working properly, that refrigerant isnt going to move around. One of the main reasons a compressor goes bad is from not being used for long periods of time, and the long cool seasons of fall and winter means that many Ohioans dont run their air conditioning for several months.
A compressor can also have problems if the clutch on the compressor gets stuck. If it gets stuck in the on position it will make your air conditioning run continuously, and if its stuck in the off position it will keep the compressor from engaging. Youll need to have your mechanic look at what is causing the problem with your compressor.
The Air Conditioning Shouldn’t Normally Keep The Idle Speed Down
Does your car idle rough when you turn on the air conditioning?
A brief initial loss of rpm as the AC comes on is normal. When the AC clutch engages to run the compressor, it places an additional load on the engine. But the car’s computer should bring the idle speed back up.
If you lose over 200 rpm and idle speed doesnt rise again, then theres a problem.
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Loud Noise When Compressor Is Running
When the heating, ventilation, and air conditioning system operates, it tends to have some noise when its kicking on and off. But the loud noise when the AC switches on is another potential symptoms of bad AC compressor. The AC compressor has several interior components and uses a sealed bearing to turn. If any of the interior components break, or the compressors internal bearings fail or seize, thenall sorts of noisescan be produced as a result. The most valuable solution is changing the whole AC compressor.
Ac Stops Working When Car Gets Hot
I drive a Volvo S40, 2006 with 45K miles. When I take the car out of my garage the AC works beautifully until the car begins to get warm. At about 30 minutes into the driving trip, only warm air blows. If I park anywhere in the sun, the AC does not provide cold air at all. The AC only works when the car is cool. I brought it to the dealer and they said the compressor is shouting off and needs to be replaced. The cost would be $1,130. I was hoping that it was low on refrigerant, which they did not check, and my son thinking that a fan belt gets loose when the car warms up. I would really appreciate your advice. When I went to the dealer it was a cool day. I drove several places that morning and the AC worked for three hours before going warm. Thank you so much!
Go to an independent auto A/C shop and get a second opinion. A/C is sensitive to ambient temperatures and a marginal system will work like that. It bothers me a bit that they condemned the compressor without hooking up gauges, but maybe they heard or saw something that told them that. A second opinion would tell you for sure.
Id toss a small can of refrigerant into it and see if the A/C improves any. You need to be mindful of accidentally overcharging the system, which is why I specified small can.
If cooling improves, suspect a refrigerant leak.
I have no idea if this is in fact whats wrong with your car, but its one reasonable explanation as to why the compressor needs replacement.
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