AC Not Working in Honda Civic Car – How To Fix?

The AC in a Honda Civic is essential for a comfortable driving experience, especially during HOT summer days. “AC Not Working in Honda Civic Car” What should you do to fix the AC system? Here, I will share my experience with the faulty Honda Civic AC system and how I fixed it.

In that case, I can’t think of taking a single ride without fixing the issue. However,  troubleshooting the a/c in the Honda Civic won’t be an easy task. Even if it’s a mechanical process and it doesn’t mean it’s a mission-impossible task. 

Yes, with a bit of mechanical and technical knowledge, you can fix it by yourself. Start learning troubleshooting tips, tricks, and hacks.

Why is AC Not Working in Honda Civic Car?

If you are a Honda Civic owner, then you can check out the following reasons that can make your AC faulty. 

  • Low refrigerant level
  • Failed compressor
  • Electrical issues
  • Failed AC control head or thermostat
  • Clogged AC filter
  • Faulty AC relay

How To Troubleshoot Honda Civic AC Not Working [ Problems & Solutions Guide]

Troubleshoot Honda Civic AC Not Working

Let’s start fixing your Honda Civic AC and enjoying a cool ride again. Here are the possible problems and solutions. 

1. Low Refrigerant Level

Low refrigerant levels are a common problem affecting the AC’s performance in a Honda Civic. The refrigerant is essential for cooling the air inside the car. If its level is low, the AC may not work efficiently. Ultimately, you may not get cool air. It usually happens because of a leak in the refrigerant system, which leads to a loss of refrigerant.

How to Fix Low Refrigerant Level?

  • Locate the refrigerant system; it is usually under the car’s hood.
  • Then Check for any visible leak in the refrigerant system, such as oil stains or refrigerant residue. If you do not identify the leak, use an electronic leak detector to identify the leak.
  • Once you have identified the leak, repair it using a refrigerant-approved sealant.
  • After repairing the leak, recharge the refrigerant system with the recommended refrigerant. 
  • After recharging the refrigerant system, start the engine and turn on the AC. Check the performance of the AC and make sure it is cooling properly.

2. Failed Compressor

A failed compressor can also be the culprit for Honda Civic AC systems. The compressor is the major part of the AC system. If it fails, the refrigerant will not be compressed and circulated correctly, leading to no cooling in the car.

How to Fix Failed Compressor?

How to Fix Failed Compressor
  • Locate the compressor; in Honda Civics, the compressor is usually located at the front of the engine bay.
  • Before beginning, disconnect the battery to avoid any electrical shock.
  • The refrigerant lines are connected to the compressor; disconnect the lines using a wrench.
  • You will find four bolts that hold the compressor in place. Use a socket wrench to remove them and carefully remove the compressor. Check the compressor if it is faulty, replace it with a new one.
  • Take the old compressor to an auto parts store to find a compatible replacement. Install the new compressor.
  • Once the compressor is installed, connect the refrigerant lines and recharge the system using a refrigerant recharge kit.
  • Finally, turn on the AC and make sure it is working properly.

3. Electrical Issues

Electrical issues are the most common reasons for the Honda Civic AC not working. A faulty AC control unit, a blown fuse, or a damaged wiring harness could cause electrical issues. When there is a problem with the electrical system, the AC system cannot receive the necessary power to operate, causing it to fail.

How do you Fix Electrical Issues?

How do you Fix Electrical Issues
  • Check the fuse box for a blown fuse. If you find a blown fuse, replace it with a new one.
  • Check the wiring harness for any signs of damage or loose connections. If you find a damaged wiring harness, replace it with a new one.
  • If the AC control unit is not working, it will not send the necessary signals to the AC system to operate. 
  • Check the AC control unit for any signs of damage or wear. If you find a damaged AC control unit, replace it with a new one.

4. Failed AC Head or Thermostat

The AC head or thermostat is responsible for regulating the temperature in the vehicle. When it fails, the AC will no longer be able to cool the car effectively. This can result in hot air being blown into the vehicle even when the AC is set for maximum cooling.

How to Fix Failed AC Head or Thermostat?

  • Locate the AC head or thermostat it is located near the radiator or near the engine.
  • Then look for cracks or other visible signs of damage to the AC head or thermostat. If you see any, it needs to be replaced.
  • You can test the AC head or thermostat using a multimeter. Connect the multimeter to the AC head or thermostat. The AC head or thermostat is faulty if the reading is not within the expected range.
  • Replace the AC head or thermostat: If the AC head or thermostat is faulty, it must be replaced. Disconnect the battery, drain the refrigerant, and remove the AC head or thermostat. Then, install the new AC head or thermostat and reconnect the battery.
  • After installing the new AC head or thermostat, refill the refrigerant according to the instructions in the manual.
  • Turn on the AC and test the system to ensure it is working properly.

5. Clogged AC filter

A clogged AC filter in a Honda Civic can cause the AC to stop working. The filter is responsible for removing dirt, dust, and other contaminants from the air that is being circulated in the car. When the filter becomes clogged, it can restrict air flow, which may reduce AC efficiency.

How to Fix Clogged AC Filter?

Fix Clogged Ac Filter
  • Locate the AC filter it is located in the engine compartment or inside the car cabin. Check your car’s manual for the exact location.
  • Once you have located the filter, remove it from the AC system. It is usually held in place by clips or screws.
  • Clean the filter using a soft brush or air compressor. Make sure to remove all the dirt and debris from the filter.
  • Once the filter is clean, inspect it for any tears or damage. If the filter is damaged, replace it with a new one.
  • When you clean and inspect the filter, it’s time to reinstall it back into the AC system. Make sure to secure it in place properly.
  • Turn on the ac and check if it is working properly.

6. Faulty AC Relay

A faulty AC relay is a common problem that can cause the AC in a Honda Civic to stop working. The AC relay is a component that helps control the power supply to the Automotive air conditioning system. When it fails, the AC can no longer operate correctly.

How to Fix a Faulty AC Relay?

  • Locate the AC relay in the relay box under the hood of the Honda Civic. The relay box is located near the battery or near the fender.
  • Once you have located the AC relay, use a multimeter to test it. The multimeter should show a reading of 12 volts when the relay is energized. If the reading is low, the relay is faulty and needs to be replaced.
  • To replace the AC relay, you will need to remove it from the relay box. Remove it by releasing the clips that hold it in place and pulling it out of the box. You will need to replace it with a new AC relay of the same type.
  • Once you have replaced the relay, connect it to the relay box by inserting the clips back into place.
  • After replacing the relay, test the ac by turning it on. If it works correctly, the faulty AC relay has been successfully fixed.

Frequently Asked Questions (FAQs):

Is it normal for my Honda Civic’s AC to make noise?

Yes, it is normal for the AC in a Honda Civic to make some noise. However, if the noise is excessive or unusual, it could indicate a problem. In that case, a professional inspection of the car is recommended.

What are some signs of a failing AC compressor in my Honda Civic?

Some signs of a failing AC compressor in a Honda Civic are as follows: 

  • Loud noises
  • Reduced cooling
  • Warm air blowing
  • Leaking refrigerant
  • An increase in the electricity bill
  • Frequent cycling on and off and 
  • Reduced airflow from vents.

Why is my Honda Civic AC blowing hot air instead of cold?

For several reasons, your AC may start blowing hot air instead of cold air. The AC system may be low on refrigerant, the compressor may be faulty, or the thermostat may be stuck in the closed position.