There's nothing quite like getting in your vehicle on a hot day, switching on the air conditioning and having warm air blow out of the vents. You may have had no problem for months and then, one day, you are driving around in a sauna. You're hot stuff, but not in a good way!
So what goes wrong when the AC isn't working? It could be a lot of things because the system has many different components. One thing that's a common cause is the vehicle is low on refrigerant (it used to be called Freon). If that's the case, it's not as simple as simply adding more. Sure, it may fix it quickly for a short time, but it's more likely than not that the refrigerant will just leak out again.
The original Freon used in air conditioners was destroying the Earth's ozone layer, so that's not used much any more. But the one that's currently used also contributes to global warming, so it's important that as little of that escapes as possible. So a technician will determine if there's a leak in your system, where it is and fix that before adding new refrigerant.
Your vehicle also has an evaporator or two, and those can fail. Leaks are often the problem with them as well. The big component that can go bad is the compressor, often a victim of age, wear or neglect.
A technician will also check to see that the blower is working correctly. That's what blows that cool air into the cabin. Sometimes the motor will fail, a relay will go bad or a fuse will blow. As you can see, there are lots of different parts involved here!
The good news is that your vehicle's service facility has the special equipment to recover the refrigerant and check the system's pressure, both vital to properly servicing the air conditioning system.
As with many vehicle components, regular maintenance can go a long way to minimizing problems in the air conditioning system. It can reduce the chance of the compressor having to be replaced, too. Pretty cool, huh?
The Auto & Tire Doctor Inc
12000 PIONEER TRL
TRUCKEE, CA 96161