Most people are incapable of diagnosing a faulty air conditioner, but by understanding these common car A/C problems and why they occur you’ll be one step closer to fixing it.
No Air is Coming Out of The Vents
If no air is being emitted from the vents, it could be a sign of:
- Obstructed air intake: Automobiles have at least two locations where air can gain entry, and they are the vents near the bottom half of your windshield along with recirculated cabin air. If either becomes blocked due to debris or the filter is clogged, the vents might not blow out any air.
- A damaged hose or belt: A/C units come with multiple belts and hoses which help the system operate. If they become blocked, disconnected, or start to leak, air will not flow properly through the vents.
- Faulty relay or blown fuse: Once a fuse becomes blown, the blower motor won’t be able to get power, which stops air from being blown into the vents. The relay is responsible for taking miniature electric currents and using them for regulating larger currents required for ventilation, but if it goes bad its ability to do this will be compromised.
The Vehicle’s A/C Is Making Unusual Noises
Any type of sound coming from your vehicle’s A/C system is definitely not good. If you’re hearing banging or rattling, it could be that road debris of leaves have entered and are blocking the internal components. It might also be a sign that an important component has failed. For example, if the bearing becomes worn the A/C will produce a squealing or grinding noise. Turn off your A/C immediately if you hear a sound as continuing to use it will worsen the situation, and it will have to be inspected by a technician.
The Air Isn’t Getting Cold Enough
If the vehicle’s air conditioning is working but you notice the air is not getting as cold as it should be, this could be an indication of:
- Low refrigerant: When an A/C system doesn’t have enough refrigerant, the pressure will be reduced which stops its clutch from being able to trigger a compressor to start its cycle.
- Faulty clutch switch: Should this part fail, your air compressor won’t be able to function which stops it from condensing liquid refrigerant so it can become gas.
- The condenser is faulty or obstructed: Condensers are responsible for transforming refrigerant from gas to liquid. However, if the condenser malfunctions or becomes blocked, air may still come out of the vents but it won’t be cold.
The A/C Produces An Unpleasant Odor
This is most likely mildew, which results from bacterial growth inside the system. It commonly occurs in vehicles where the air conditioning isn’t regularly used or the driver usually keeps it at the highest setting, resulting in excess moisture levels which attract fungi, mold, and bacteria which will often thrive behind the vehicle’s dashboard near the evaporator. It is their presence that creates an unpleasant odor. To solve it, the air filter will probably need to be replaced and you will want to apply an antibacterial-based solution near the evaporator to eradicate the microorganisms.