Bringing Your Climate Issues Under Control

Few things are more critical to driving comfort than your vehicle’s climate controls. Whether you’re looking to cool things off with a blast of AC or add a little heat to a cold winter drive, the climate control system plays an essential role in overall driveability. While features like power-adjustable seats and leather upholstery might add a touch of class to the interior, they don’t amount to much if you’re dealing with a ride that leaves you shivering or sweating throughout the journey.

That said, climate control systems don’t always hold up their part of the bargain. Prone to breaking or underperforming, a bad AC system or heater can turn an otherwise well-functioning vehicle into an uncomfortable driving experience for all involved. If you’ve noticed that your morning commute hasn’t been as cool (or warm) as it once was, a quick check-up at your local auto repair shop near Stockbridge might be in order.

Before you call in the pros, take a moment to review our guide to some common climate control-related symptoms, causes, and fixes. Familiarizing yourself with some of these issues is a great way to jump-start the repair process and ensure you get a fair, accurate quote when you bring it in for a fix. From malfunctioning heaters and AC compressors to busted fans and clogged vents, read on as we learn how to take control of your vehicle’s climate-related issues…

Symptom: AC Isn’t Cold Enough

Cause: Low Refrigerant

An air-conditioning system that just can’t seem to reach the desired temperature is one of the most common climate control-related issues. This is due to the fact that, no matter which make or model you’re driving, all vehicles need their AC’s refrigerant replaced on a regular basis. This refrigerant—often referred to by the brand name Freon—has some unique properties that make it the perfect choice for mobile cooling; this is primarily thanks to Freon’s ability to shift between its liquid and gas forms, which allows it to efficiently absorb heat and create cooler air.

On most modern vehicles, the AC’s refrigerant needs to be replaced about every two years. Failure to follow this schedule can result in a cabin that just doesn’t get quite as cool as it used to, which can lead to some serious discomfort for those living in warmer climates. At an average cost of $150 to $300, a refrigerant recharge isn’t the most expensive chore on your vehicle’s maintenance schedule and can go a long way toward improving overall comfort.

Cause: Failed Condenser or Clutch Cycling Switch

Refrigerant might not always be the culprit when it comes to an AC system that’s struggling to meet expectations. In some cases, the problem could come down to a malfunctioning or blocked AC condenser, which is the competent responsible for converting the refrigerant from its gaseous state to its liquid state. In rare cases, the AC’s clutch cycling switch might also be behind the problem.

Designed to ensure the pressure of the AC system remains at the desired level, a malfunctioning clutch cycling switch can lead to all sorts of cooling-related problems. Both the condenser and cycling clutch switch require professional replacement due to the tricky nature of AC-related repairs. A cycling clutch switch is a relatively cheap fix with an average cost of $200, but expect to pay more than $600 if a full condenser replacement is in order.

Cause: Heater Control Valve

If your vehicle’s heating system is on the fritz, it can create some noticeable issues when trying to cool the cabin. Many vehicles employ a design that sends cold air through both the AC compressor/condenser and the heater core before flowing out of the vents. This approach normally wouldn’t cause any issues, but if your heater control valve is malfunctioning, it can be a whole different story.

This sort of malfunction can cause the heater core to essentially be stuck in an “on” position, warming the cold air from the AC system and creating a lukewarm mix that can create no shortage of frustration for a sweaty driver. Luckily, this issue is pretty easy to diagnose: if the vents are still blowing hot air even when the AC system is off and the climate controls are set to the lowest temperature, you’re probably dealing with a bad heater control valve. A mechanic can do a final diagnosis with the typical repair ringing in at around $350.

Symptom: No Cold Air

Cause: Refrigerant Leak

If your AC fails to produce ANY cold air, a lack of refrigerant could well be the issue. All vehicles need a little refrigerant recharge from time to time, but if the problem has got to the point where your AC can’t even come close to hitting its temperature target, it could signal a leak in the system. Whether they’re located in the AC compressor, condenser, evaporator, or hose, even the smallest leaks can result in some big problems next time you try to cool off your car.

Diagnosing a refrigerant leak can be difficult for one simple reason: given its gaseous state, you’ll almost never find that tell-tale pool of refrigerant that clearly indicates a leak in the system. That said, some drivers might notice a sort of greasy buildup on the AC system’s hose connections, but to truly narrow down the issue, you’ll need to make a trip to your auto shop of choice. There, mechanics can add a fluorescent tracer dye through the system, which, using a blacklight, can help to pinpoint the leak. Once the compromised part is found and repaired, you’ll just need a quick refrigerant recharge, and you’ll be enjoying cool air in no time.

Cause: Bad Compressor

Given its role in circulating air through the AC system, it’s hard to underestimate the importance of a good compressor. When this vital part fails, you’ll tend to notice in a hurry as it’s usually accompanied by a total lack of cool throughout the system. If you live in a colder climate where your AC system doesn’t get regular, year-round use, a failed compressor should be your first suspect when diagnosing an AC-related issue.

The bad news is that an AC compressor is a relatively pricey fix with an average cost of $1,100. The good news is that it’s pretty easy to avoid this sort of automotive malady by running your AC on full power for at least ten or fifteen minutes every month.

Symptom: Smelly AC

Cause: Mold or Mildew

If you’re the type of driver who rarely uses their AC, owns an older vehicle, or often runs the system on its coldest setting, don’t be surprised to be met with some less-than-pleasant odors next time you try to cool off the cabin. These conditions can create the perfect environment for mold and mildew to flourish, which can result in stinky, musty air emanating from your vents due to the extra moisture that becomes trapped in the system.

In most cases, this problem can be easily alleviated by replacing a vehicle’s cabin air filter. This filter, often found behind the glove box, is different from the engine air filter located under the hood and should be changed every 15,000 miles. This will not only reduce any foul odors from the AC system but also filter dust, dirt, pollution, and other contaminants from the air. If you’ve tried replacing the filter and are still met with a distinct mildew smell from the AC vents, you might need to make an appointment with a mechanic who can add a specialized antibacterial agent to the evaporator, though this isn’t very common.

Symptom: Pooling Water

Cause: Faulty Evaporator Coil

Located behind the dashboard, the evaporator coil is used to absorb heat and combat humidity—a task that keeps it moist with condensation and leaves it susceptible to bacteria and mold buildup. If this buildup is relatively mild, it’ll result in nothing more than a musty mildew smell, but if left untreated, it can block the evaporator coil’s drain line. When this happens, condensation can start to pool in the evaporator heater box, where it’ll eventually overflow and begin leaking into the cabin itself.

If you notice a suspicious pool of water on the passenger-side floor accompanied by a moldy smell, make an appointment with your local mechanic for an evaporator drain hose replacement. The hose is a relatively cheap part with an average cost of $10 to $30, but labor could run the job into the $200 range.

Symptom: Lack of Air

Cause: Blower Motor

Turning the heater on to be met with cold air—or vice versa—is certainly no picnic, but what if your vehicle’s vents aren’t producing any air at all? In that case, there are three prime suspects you should keep an eye on: a failed blower motor, blocked air intake, or damaged belts and hoses.

Whether you’re talking about heating or cooling, both ends of a vehicle’s climate control spectrum need a blower (which is essentially a fan) to deliver the warm or cold air. If your vents are stagnant, it could be as simple as a blown fuse or relay in the ventilation system. If replacing the fuse or relay doesn’t do the trick, checking the blower motor or blower resistor is the next step. These sorts of malfunctions happen with age and heavy use and can cost anywhere between $100 to $500, depending on whether the motor resistor or motor is to blame, respectively.

Cause: Intake Issue

A damaged belt or hose could also be the reason for a lack of air, but sometimes fixing the problem can be as easy as giving your vehicle a little much-needed TLC. You see, the air that’s fed into the AC system comes from two places: the air already within the cabin and a vent located just below your windshield.

Given the sloping nature of windshields, these latter vents are primed for the sort of blockages that can make it difficult for the AC system to draw in enough air to get the job done. Regularly cleaning the vents located under the front windshield can have a big impact on AC performance, especially if you live in an area where fall foliage leads to a lot of debris becoming plastered over the intake.

Symptom: Lack of Heat

Cause: Low Coolant

A lack of AC can be annoying during warm-weather driving, but a lack of heat can be downright dangerous between the sheer distraction and the cold hands that can make it difficult to manipulate your vehicle. When diagnosing common heat-related issues, the coolant tank should be your first stop.

As the name implies, this fluid is responsible for keeping things cool, but it also plays an important role in heating as it helps to transfer heat from the engine to the car’s heater core. A lack of coolant can make this difficult, so if your vehicle still isn’t warming up after the engine has been on for a few minutes, pop the hood and make sure your coolant is within the recommended range.

Cause: Heater Core

A heater core is basically a small radiator located within your vehicle. Composed of metal tubing, the heater core distributes hot air throughout the vehicle using a series of small fans. If the heater core experiences a clog, leak, or some other malfunction that prevents coolant from flowing through the tubing, the signs will be pretty obvious. These include an overheated engine, chronically low coolant level, and a distinct, sweet smell throughout the cabin that signals leaking coolant.

In some cases, the additional moisture caused by the faulty heart core will create a moist interior, so keep an eye out for foggy windows. A heater core is not a cheap fix, with prices ranging between $800 and $1,200, but you might be able to get away with putting off the work if you live in an area with mild winters.

Seek Solutions for Your Climate Control Issues

While most drivers understandably tend to focus on those repair and maintenance tasks that keep the wheels turning and engine humming, keeping a vehicle’s climate control system in good working order is an important part of the car care equation. That morning commute can be tough enough without having to worry about freezing behind the wheel or showing up to work looking like you just completed a half-marathon, which is why it’s so important to familiarize yourself with some of the common warning signs of a faulty AC system or heater.

In most cases, these problems are relatively easy to diagnose—and while important parts like heater cores and AC compressors can set you back more than $1,000, most climate control-related repairs are a little easier on the wallet. If your heater isn’t quite as warm as it once was, or your AC is struggling to keep the cabin nice and cool, there’s no reason to settle for the new normal. Spend a little time tracking down the issue, research simple repairs, and if the project falls outside your comfort zone, make way for your trusted auto repair shop.