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Air Conditioner Components
Your car’s air conditioner features five main components:
R1234yf refrigerant leak detector and sealant
A failure in any of these parts can prevent your air conditioner from working properly.
The AC system in your vehicle is set and sealed at the factory with an exact amount of refrigerant gas—known as a charge—and a precise pressure level. The refrigerant used in most modern cars is either R134A or the newer R1234YF. (Older cars may still use discontinued R12 freon.)
Read: How to Recharge a Car’s Air Conditioner
If there’s a leak in the system and the refrigerant has escaped, the air conditioner will not blow cold air until the system is recharged or repaired.
Troubleshooting the AC
Even if you stay on top of routine maintenance, there are numerous reasons why your air conditioner might fail. Older vehicles are particularly susceptible to refrigerant leaks or part failure due to the system’s prolonged exposure to heat, vibration, corrosion from road salt, and normal wear and tear.
Let’s consider the most likely causes of a broken air conditioner.
Shop now for car AC partsLeaks – Leaks are the most common problem when an air conditioner is broken. They can come from numerous places, such as the compressor, hose manifold, various seals and pressure switches, or pin holes in the condenser.
AC condenser for 2016-2020 Chevrolet Malibu
Blocked or broken air conditioner condenser – The condenser converts the refrigerant gas into a high-pressure liquid and then cools it. Air from the fan flows through your vehicle’s air vents to cool your vehicle’s cabin. The cabin will not be cooled properly if air doesn’t flow freely.
Inoperative temperature sensors – AC control systems require at least two sensors: one to measure outside air temperature and another to measure the temperature inside the vehicle. Some higher-end vehicles have even more sensors with advanced measuring technologies, though most newer models have several cabin sensors. If these sensors fail or are faulty, it can cause the AC to fail since the reading will be different from the actual cabin temperature.
Broken cooling fan – Your vehicle has fans that blow the cooled air into the cabin through the instrument panel, floor, and windshield vents. If the fan isn’t functioning correctly, the culprit could be blown electrical fuses, electrical shorts, or damage from road debris.
The door blend actuator is a frequent culprit when the air conditioner’s broken.
Damaged blend door actuator – A blend door facilitates air moving to the heater or cooling fan to blend and mix the air circulating inside your vehicle. It is possible for the door to warp and the blend door actuator to fail over time. When you first turn on the air conditioning, you might hear knocking, clicking, or unusual sounds like squeaking or droning from the dashboard area. As the problem worsens, the sound could get louder.
Failure of the compressor relay module – The relay module powers the system’s clutch and compressor. The air conditioner won’t work if the relay has failed because the relay drives the AC compressor.
Insufficient vehicle battery – As your battery ages, weakens, and loses power, your air conditioner may only function marginally or not at all. The battery may be strong enough to power the rest of the vehicle but fall short of powering the air conditioner.
Engine control module (ECM) error – Your vehicle’s control panel functions via the engine control module, the brain of your vehicle. This critical part controls almost everything, including the ventilation system. An error or failed ECM could cause the ventilation system to malfunction, rendering the control panel inoperable.
Replace cabin air filters. Don’t try to clean them.
Clogged filter – A filter prevents dirt and debris from forming in the evaporator coils. If the filter is clogged, buildup on the coils will cause them to freeze, preventing air from passing through the evaporator and cooling the cabin. This is one of the easiest problems to remedy when the air conditioner’s broken.
Faulty wiring – The AC system uses a network of wires, cables, and connectors throughout its various functions, including the defrosting cycle. Take the time to hunt for broken air conditioner wires, as well as frayed or disconnected wires caused by age, excessive heat, rodents, or debris. Any of these factors will cause issues.
If the serpentine belt is broken, it affects the air conditioner, as well as other engine components.
Worn serpentine belt – Your air conditioner has either a V belt or a serpentine belt that connects the AC’s compressor to the engine crankshaft, allowing the compressor to turn and operate using the engine’s power. As either type of belt ages, it can stretch, fray, or even separate. If this happens, the AC and other engine accessories will cease functioning, and the belt needs replacing. A telltale sign is the loud squealing of a worn, slipping belt while revving the engine.
Read: What Is a Serpentine Belt and How Do You Change It?
Cost to Repair an Air Conditioner
Whether or not your vehicle is still under warranty, we strongly recommend that you avoid attempting to repair an AC system yourself. Government environmental regulations regarding refrigerant use and disposal must be adhered to, and specialized equipment is required to service an air conditioner unit correctly.
Many AC repairs require specialized equipment.
DIY kits are available for purchase and might help in the short term. However, misusing them could cause more severe damage or mask serious AC problems, leading to expensive repairs in the future.
Most facilities charge to diagnose your vehicle’s AC problem. Hourly rates and shop labor rates vary geographically. A 2023 survey by Motor.com of hundreds of repair shops around the country indicated a rate as low as $75 per hour in some areas to a high of $297 per hour. Between $120 to $150 per hour seems to be a reasonable average. Of course, the problem, complexity, and severity of the issue, along with the make and model of your vehicle, will impact what you ultimately will pay.
According to Kelley Blue Book’s fair repair range report, the average costs for common AC repair services are:
- AC repair: $384 to $445
- AC compressor replacement: $1,546 to $2,500
- AC recharge: $239 to $281
Tips for Maintaining Your Vehicle’s AC
- Check your vehicle’s engine and cabin air filters as recommended in your owner’s manual and replace them as needed.
- Have the AC system checked by a professional every two to three years, including the compressor, evaporator, and condenser.
- Have the system checked as soon as possible if you notice any strange or unusual noises coming from your AC system.
