Auto Air Conditioning Repair Basics: Common Symptoms & Problems

by Marjorie, Cars for Keeps Social Media Manager

A broken air conditioner in your automobile gets put at the bottom of the "to-do" list all winter long. As we move into another warm, humid Michigan summer, however, suddenly having a car air conditioner that works - and works WELL - is of the utmost importance. Who wants to arrive at a meeting, the mall, or a friend's house sweating and flushed by stale, hot car air?

Having an auto air conditioner that "kind of" works may get YOU by, but faulty air conditioners can cause bigger damage to your car down the road if left unattended. An air conditioner running low on coolant, on dirty coolant on faulty electrical wiring can end up ruining the entire air conditioning compressor. Car air conditioners are connected to the rest of the vehicle's electrical system, meaning a surge or problem with the air conditioner can cause problems with the rest of the car, causing poor idling, fuel inefficiencies or drained batteries.

Generallly, auto air conditioners are fast, easy and inexpensive to fix. Most car air conditioning problems are coolant-related, and may often be as simple as getting a coolant flush, refill or fixed leak.

With that said, your car's air conditioners is not one of those devices most technicians recommend fixing at home, unless you're a qualified mechanic. Most do-it-yourself instructions for fixing broken auto air conditioners contain scary phrases, like "it is illegal to release freon gas into the atmoshere" and "be sure to wear proper hand and eye protection". Plus, there are many different things that could be wrong with the car's air conditioning system.

Here are a few of the problems most commonly found in auto air conditioners:

1) Coolant and/or Refrigerant Leaks. This generally applies to older, less computerized vehicles. Refrigerant can run out on its own over the course of time, or leaks may have developed in the car's AC compressor or one of its hoses. If your vehicle has never had a coolant flush or refill and it's pushing 150,000 miles or more, it's probably time.

2) Noisy AC Compressor. Noises that occur when your car's AC is turned on can come from minor engine noises or hoses, but they could also be symptoms of problems with the compressor. If the problem is the AC compressor, it will likely have to be replaced.

3) Fluctuating Temperatures. When a car's AC blows out air with sporadic temperatures, it's often likely that moisture is building up in one of the hoses or assemblies, causing ice to accumulate and clog. Removing ice from a car's air conditioning assembly is a short and easy procedure.

4) Faulty Car Electrical System. A weak car battery can cause your auto air conditioner to function weakly or not at all. Car batteries need to have enough voltage to trigger the AC compressor, and while it may be strong enough to run the rest of your car, it may still be too weak to run your car's air conditioning.

5) Bacteria Buildup. Funky smells emanating from your car's air conditioning vents are likely caused by a bacteria buildup in the evaporator. Good auto mechanics (like Cars for Keeps!) will have the proper tools to flush the evaporator out quickly and without much cost.

So what are some basic ways to tell if any of these are a problem for your car's air conditioning unit? Here's a basic checklist of symptoms which indicate something is wrong with your auto AC:

- If the AC system doesn't produce cold air (duh)
- If the fan or blower doesn't work
- If the fan, blower or AC is noisy when turned on
- If one of the dashboard controls malfunctions
- If the vent, car heater or defroster are having problems working correctly
- If the air conditioning smells funky
- If the car has a tendency to overhead
- If the air filter or dryer have never been replaced, or if the AC has never been serviced before

If one of these symptoms applies to your car's air conditioning system, it's probably time to have it inspected by a mechanic. Caught early, most auto air conditioning problems are fairly easy and inexpensive to fix.

Stay cool!