How to Diagnose AC Problems in a Car

There’s nothing worse than a faulty air conditioner when the temperature starts rising. Your vehicle should be an oasis from the heat and humidity of summer, so it’s important to keep your AC working properly. From warm air to unusual smells, here are a few common issues that may be affecting your AC. Before you call your local auto shop, here are a few simple steps on how to diagnose AC problems.

Here are  4 common issues that may be affecting your car AC

Unusual Odors

Does your car smell like your gym bag? If unpleasant odors are coming from your vents while your AC is on, there are two common issues. First, it could be caused by an old filter. A dirty air filter can be bogged down with dirt, grime and mold, which creates an issue with your air quality. Thankfully, this is a relatively easy and hassle-free way to fix your air conditioner.

On the other hand, your odor issue could also be caused by a buildup of mold on your evaporator case. This happens when water leaks into or accumulates in your evaporator case. Mold is tricky to properly clean out, so it’s best to call a professional auto shop to thoroughly clean your AC evaporator.

Alternating Hot and Cold Air

Sometimes your AC acts like someone is constantly changing the dial. A constant shift from cold to hot and back can be caused by a variety of issues. Here are just a few likely culprits with this AC problem:

  • Bad compressor clutch
  • Blown fuse
  • Leaking AC system
  • Expansion valve clog

While a blown fuse can be easy to fix, the rest of the problems typically require a more experienced technician. Try using a car code reader to diagnose the specific issue with your AC.

Lack of Cool Air

Warm air blowing through your vents isn’t what you expect when you crank up your AC. If your cool air is feeling warmer than usual, it’s likely that you have a leak in the system or a damaged component.

A vacuum leak, failed o-ring or clogged expansion tube can all keep your AC from cooling properly. More serious issues could be a damaged blower motor, resistor, compressor, compressor clutch or simply a blown fuse. A leak, once you discover the location, can be much easier and more affordable than a damaged component.

Low Airflow

Finally, many air conditioners begin to lose power as they age. Low airflow from your system, even with the fan speed turned up, can be caused by a number of damaged or clogged components.

First, inspect the evaporator core for any signs of mold or mildew buildup. This is one of the easiest problems to fix, and it’ll also improve your air quality. Many times a loose hose can also cause the air to be blown out in your engine compartment rather than your vents. Other issues could be your fan, control knob or seals and o-rings.

Once you’ve determined the cause of your AC problem, it’s time to get to work. From replacement o-rings to an AC recharge kit, find everything you need at your local auto store. Find the solution on your own or visit a trusted mechanic to enjoy cool, fresh air all summer long.

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