In the summer, a faulty air conditioning (A/C) system in a hot car is an absolute nightmare. Let’s go over some common A/C problems that prevent cold air from blowing, how to solve them, and some tips to maintain this essential summer feature of your car.
Why is my car AC not blowing cold air?
Quick checks
To find out why your A/C isn’t blowing cold, start by checking if your cabin filter needs replacing. A dirty filter will prevent air blowing through. You can find steps on how to change it here.
A common misconception is that you can cool your car simply by turning on the ignition. To know whether your A/C really works, drive around to give it the chance to circulate the air.
If these solutions don’t fix your A/C issue, there may be a more technical problem to address.
Refrigerant leak
Refrigerant circulates through your A/C system, expanding into a gas and contracting into a fluid as it removes heat and humidity from the cabin. As a fluid, refrigerant can look oily, so look for oily patches around the A/C.
A loud clicking sound when the A/C is running could be a sign of a refrigerant leak. Without enough refrigerant, the A/C can’t function correctly. Take your car to a professional to fix a leak for you.
Broken compressor
The compressor circulates refrigerant throughout the A/C system. In case of a breakdown, the refrigerant cannot reach the condenser to be cooled.
A chattering or whining sound may indicate a broken compressor, which will need to be professionally replaced.
Faulty condenser fan
The condenser fan keeps the refrigerant cool so the A/C system can generate cold air. If it’s clogged, it may make a rattling sound and won’t be able to cool the refrigerant. You may be able to unclog the condenser yourself—you’ll find it between the radiator and front grille.
If all A/C components are functioning properly, hot air may be caused by an electrical issue, such as a frayed wire or blown fuse, or the A/C system may require a recharge, which you can do yourself.
Recharging your A/C
If you notice your car’s A/C system is losing power, try recharging it. To do this, you’ll need:
- A/C recharging kit
- refrigerant
- safety glasses
- gloves
Once you’ve gathered your materials, follow these steps:
- Start your car and set the A/C to high.
- Look under the hood to see if the clutch on the compressor is engaging. It should spin with the accessory belt. If it is, the system likely just needs more refrigerant. If it’s not, the refrigerant could be very low, there may be an electrical problem, or the compressor may have failed.
- Turn off the car and find the low-side pressure port. This is usually on the passenger side of the engine bay with a black or grey cap with the letter “L” on it.
- Attach the charging hose from the A/C recharging kit to the low-side service port.
- Restart your vehicle. With the A/C on high, watch the gauge on the charging hose. If the pressure is under 40 psi, the AC system is undercharged.
- Thread the refrigerant can onto the charging hose. Hold the can upright and squeeze the trigger for 5 to 10 seconds. Check the pressure gauge to make sure you don’t overcharge the system. Repeat until you reach 40 psi.
- Check if the A/C is blowing cool air. You can use a thermometer to confirm that the temperature has dropped.
If your A/C system still isn’t working, have it assessed by a professional at a NAPA AUTOPRO service centre.
(A/C systems made before 1995 typically can’t be recharged.)
Maintaining your A/C
To avoid expensive repairs, help your A/C stay in good condition with these tips:
- Run the A/C on defrost mode for 10 minutes every week throughout the year. Set the temperature to the coolest setting and turn the fan on maximum speed.
- Don’t pre-cool your car; the A/C operates at maximum efficiency while you’re driving.
- Clean or replace the cabin air filter at least once every 12 to 24 months.
Pay attention to changes in your A/C system, including strange noises, smells, or warm air. Solving these issues early is best for the health of your vehicle, your safety, and your wallet!
For any questions about maintaining your A/C system, visit a NAPA Auto Parts store to speak with an expert.
Author: 
No comments 
