Three Things That’ll Kill Your A/C This Summer

Air Conditioning Button

Your ride’s air conditioner is one of many features that’s expected to work flawlessly and with minimal second thought. With the heat of summer setting in, the time is right to give this all-important system some attention and TLC, to help ensure optimal performance for the miserably muggy months ahead.

Like many features of your family hauler, the air conditioner is made up of parts, electronics and components that can wear out, break, or otherwise fail, requiring attention. But remember: numerous air-conditioner-related issues may actually stem from relatively small problems that are inexpensive or free to fix, provided you read your owner’s manual, partake in regular maintenance, and find problems early.

Read on for a list of three common causes of A/C system problems, and some pointers to save yourself time, money, and a car-full of crabby, sweaty passengers.

Problem: Your cabin air filter is clogged

Clogged Cabin Air Filter


Like all filters, your ride’s cabin air filter, if equipped, requires periodic replacement once it becomes clogged up with dust, dirt and debris. In general, this part needs to be changed about once a year, at a cost of about $20. A plugged cabin air filter stresses your A/C system, causes it to work harder, prevents a full volume of air from flowing through the system, and can allow excessive frost and ice buildup on vital A/C parts, which can result in water leaks into the cabin, and other issues. If your cabin air filter is plugged, your entire climate control system will struggle to operate efficiently, and you’ll overwork your A/C system, possibly damaging components within, and wearing it out faster. With a plugged cabin air filter, your A/C system simply can’t move a sufficient volume of cold air into the cabin to cool it as intended.

The Pro

Automotive service technician John Kennard comments, “As summer sets in, we get lots of customers at the shop complaining of poor A/C performance. About a third of the time, the problem is a clogged air filter. It’s nice when customers come in expecting a big repair bill, and I replace their cabin air filter for about $20, and send them on their way – with an A/C system that’s working much better. It’s funny though – when I ask many customers when they last changed their cabin air filter, a lot of them look at me like I have three heads. It’s surprising how many people don’t know what a cabin air filter is, or that it needs to be changed.”

The Gist

If you aren’t aware that cabin air filters are a thing that exists, and if your A/C system is performing poorly, there’s a good chance it’s being suffocated by a dirty filter. Check your owner’s manual for the service intervals, and replace as needed. In many cases, a dirty cabin air filter can be swapped out with few if any hand tools, and often right in your driveway, without a visit to the shop.

Problem: Your condenser is damaged, or plugged full of crap

Air Conditioning Condenser


A condenser looks like a radiator, full of fins and tubes through which air passes to release heat from the refrigerant in the A/C system. It’s not unlike the radiator in your vehicle, though the condenser is designed to release heat from refrigerant vapour, not engine coolant. Sometimes, condensers can become clogged with dirt, debris, bugs, and (especially) leaves, which block precious air flow, and prevent heat from being pulled from the refrigerant. When that’s the case, air conditioner performance suffers, and with a major blockage, the A/C system may even switch itself off. Sometimes, the fins on the condenser get damaged by rocks and road debris, which bends the fins out of place, restricting air flow.

The Pro

Kennard mentions, “The A/C condenser can be a tricky thing. In some cars, they’re protected well and don’t get a lot of debris or damage, and in others, it’s the opposite. For the average owner in their driveway, the condenser can be hard to locate or access. Usually, the cabin air filter is the culprit, but we see some A/C system problems caused by clogged or damaged condensers, too. Usually, you just clean it out – using compressed air or a stream of water from the hose, to remove dirt and leaves. If you’ve got both a clogged condenser and cabin air filter, you’re a/C system is probably barely working. Just ensuring both of these parts are clean and flowing properly can make a big difference in the performance of your system.”

The Gist

Though the condenser is less likely to be causing your A/C system problems, ensuring it’s clean and in good shape with a regular inspection and blast from the garden hose can help maintain A/C system performance.

Problem: There’s a leak, or some electronic issue

Cabin Air Intake Fan


Leaks and electronic issues go hand in hand when it comes to air conditioner problems, since your ride’s A/C system has a variety of sensors that are used to detect things like refrigerant pressures and temperatures, to keep the system running properly. Though a refrigerant leak, possibly caused by a bad O-ring or damaged plumbing, can cause the A/C system to shut itself off when detected by the appropriate sensor; a bad sensor, or wiring, can send a false signal to the computer that controls the system, possibly shutting it down, even if there’s nothing wrong.

The Pro

Kennard says, “So many customers come in with A/C problems expecting the worst – but more often than not, the system is in good shape, but there could be a small leak, a bad sensor, or even a faulty ground, causing havoc. Modern A/C systems are highly computer-controlled, which is both a good and a bad thing. It’s good because it allows me to run a variety of tests, quickly and easily, to zero in on any problems. But it’s a bad thing, because like computers often do, they can act up. I always tell customers, if you’re having A/C problems, it usually takes me about ten minutes to find the cause – and often, it’s not a big or complicated fix.

“Just last week I had an older Dodge Caravan with non-functional air conditioning. The customer expected a huge bill, but the culprit was a $50 temperature sensor that had been damaged by a rock.

“Keeping your A/C ticking is, largely, a function of regular maintenance and inspections, but don’t put them off. If there is a refrigerant leak, for instance, it’s much cheaper to repair it right away, than it is to replace parts damaged when that leak allows damaging moisture into the system.”

The Gist

Your favourite automotive technician can track down small A/C system problems quickly, and often, before they turn into much bigger (and pricier) ones – provided you visit your dealer or service centre for an inspection sooner than later. As it goes with many parts of your ride, you can spend a little on a repair now, or a lot later on.

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Justin Pritchard
Justin Pritchard is a native of Windsor, Ontario – though he’s called Sudbury his home for the past 20 years. Justin is a full-time auto writer, consultant and presenter of EastLink TV’s AutoPilot. His work can be seen weekly in numerous outlets across the country. When not writing about the latest new models and industry trends, you’ll probably find him fixing his 1993 Toyota MR2 GTS.
Justin Pritchard

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  • Mekanik Evony

    As an automotive service technician with over 40 years experience, I can concur with nearly every point brought to bare within the aforementioned article. As is mentioned in the article, maintenance is the key to proper operation and survival of the A/C, and many other systems on your vehicle. Regular oil changes and brake/steering/suspension inspections will help keep your ride mobile for years to come. A repair today is worth thousands more than a replacement tomorrow.

  • Johnny Appleseed

    My Civic AC shit the bed. AC shops and dealer wanted over a grand to fix it. I ordered a clutch kit from ebay for under a hundred bucks and fixed it in the yard in a few hours. They remind me of muffler shops LOL.