A working air conditioner is not only about comfort on hot days. It also helps clear a fogged windshield. Here are the most common signs that the system needs a look.
Warm or only slightly cool air
If the air from the vents is not as cold as it used to be, the system may be low on refrigerant (which usually means there is a leak somewhere), or a part such as the compressor or a fan may not be working properly.
Weak airflow
If the air is cold but barely comes out of the vents, a clogged cabin air filter or a problem with the blower fan is a common cause.
Cold, then warm, then cold again
Air that keeps switching between cold and warm can point to an electrical problem, a cycling compressor or a blockage in the system.
Unusual noises
Rattling, squealing or grinding that starts when you turn the AC on can come from the compressor or its drive belt.
A musty smell
A damp, musty smell from the vents is often caused by moisture and mold building up around the evaporator or in an old cabin air filter.
Water inside the cabin
A small puddle of clear water under the vehicle while the AC is running is usually normal. This is condensation draining away. Water on the floor inside the vehicle, however, can mean the drain is blocked.
Leave refrigerant work to trained technicians
Vehicle AC systems are under pressure and contain refrigerant that must be handled with the right equipment. In the US, technicians who service vehicle AC systems must be certified to handle refrigerant.
A simple habit
Many owner's manuals suggest running the AC for a few minutes regularly, even in cooler months, to keep the system working well. Check your manual for advice on your vehicle.
This article is general information. Every vehicle is different, so check your owner's manual and have a qualified technician inspect any problem you notice.
