Why does my A/C have weak airflow?

Weak airflow from your car’s air conditioning (A/C) system can stem from several potential causes. Here’s a breakdown of the most common reasons and what you can do to address them:

1. Clogged Cabin Air Filter

• Cause: Dust, dirt, pollen, and debris can accumulate in the cabin air filter, restricting airflow.
• Solution: Check and replace the cabin air filter (typically every 12,000–15,000 miles or as recommended by your vehicle’s manual).

2. Blower Motor Issues

• Cause: The blower motor, responsible for pushing air through the vents, may be failing or operating at reduced efficiency.
• Solution: Inspect the blower motor and replace it if worn out or damaged.

3. Blower Motor Resistor Malfunction

• Cause: A faulty resistor can prevent the blower motor from functioning at certain speeds, reducing airflow.
• Solution: Replace the blower motor resistor.

4. Clogged or Blocked Vents

• Cause: Vents may be obstructed by objects, dust, or debris, reducing airflow.
• Solution: Check for blockages in the vents and clean them thoroughly.

5. Mold or Debris in the Evaporator Core

• Cause: Mold, dust, or other contaminants on the evaporator core can restrict airflow.
• Solution: Have the evaporator core cleaned by a professional.

6. Damaged or Disconnected Ducts

• Cause: Air ducts behind the dashboard can become disconnected or damaged, leading to reduced airflow.
• Solution: Inspect the ducts for leaks or disconnections and repair as needed.

7. A/C System Freezing

• Cause: Low refrigerant levels or a faulty expansion valve can cause the evaporator to freeze, reducing airflow.
• Solution: Check refrigerant levels and inspect the system for freezing. Refill or repair as necessary.

8. Electrical Problems

• Cause: Faulty wiring or a blown fuse can prevent the blower motor or other components from functioning properly.
• Solution: Check the A/C system’s fuses, relays, and wiring.

9. Vacuum or Control Issues

• Cause: Some cars use vacuum or electronic actuators to control airflow direction. A fault here may lead to weak airflow.
• Solution: Inspect the vacuum lines or actuators for damage and repair them.

My A/C doesn’t seem as cold.

So your air conditioning doesn’t feel as cold as it once did? This is another common problem we see . Your air conditioning system is complex and has many different components. It’s best to take your car to your local who knows exactly what to test for and has the proper equipment to do so.

That said, there’s no harm in checking things out yourself to diagnose the problem.

Inspect your condenser. It’s  located in front of your radiator and should be clear of debris. If it’s really dirty, it can’t function or cool effectively.

Towards the front of the engine, by the grill, you’ll usually find the car’s A/C compressor. It looks like a small motor with a wheel on the end. with the A/C turned on this wheel should be spinning. If this wheel is not spinning, your compressor clutch isn’t working or you may have an electrical issue.

If your refrigerant levels are running low, the A/C system won’t provide any cool air. It’s important to note that refrigerant is not consumed during normal operation, however, if the system is low on refrigerant it is due to a leak. A/C systems can’t just be “topped up” the leak must be located and repaired before more refrigerant is added. Checking levels and for leaks requires specialized equipment so checking for leaks on your own is quite difficult.

One method of checking for refrigerant leaks involves injecting ultraviolet dye into your A/C system, running the car, and checking for leaks with a UV light. If you suspect your refrigerant levels might be low, we recommend calling your local immediately, before the problem gets worse. When moisture and refrigerant mix together, they form a corrosive acid that will destroy seals and components, causing more issues.

What is that…smell?

Your air conditioner is designed to blow cool, filtered air into your car’s cabin. Unfortunately, many drivers are greeted by a musty odor in their car when they first run the system for the season. In addition to being annoying, it can be harmful to your health. Potential causes of odors in your vents include dirty or old air cabin filters, or mold accumulating on the evaporator case because the drain is blocked.

What do I do next?

Once again, we can’t stress enough the importance of addressing issues with your car’s air conditioning as soon as possible. It could mean the difference between a small fix and a major repair.