Views: 13 Author: Site Editor Publish Time: 2018-06-19 Origin: Site
1. Turn the car auto air conditioning on while the car is running.
The air conditioner won’t run properly unless your engine is running. The best setting for diagnosis is “fresh air” (not recirculated) with the air blowing out of the center vents in the dash and the air conditioning turned on.
2. Notice the air pressure.
Turn the air pressure to the high and low settings and see if the airflow changes like it normally does.
3. Smell the air coming from the vents.
If there are unusual smells, you could have a leak. You may also need to change your cabin air filter.
4. Listen for unusual noises coming from the AC.
Noise could indicate that there is a problem with your compressor and that it needs repair or replacing.
5. Feel the air coming out of the vents.
You will need to know if the air is cold, room temperature, or hotter than the air around it.
Also note if it starts cold but turns warmer, or if it is usually warm but blows cold intermittently.
6. Inspect your car’s fuses.
Check your owner’s manual for the location of your car’s fuse panel, as it may be under the hood, in the trunk, or even in the driver’s foot well area. A blown fuse can cause your AC to stop working.
7. Diagnosing airflow problems
Check all of the vents.
Be sure that air pressure is coming out of the vents that you have selected. Move the vent selector to see if the air moves to the proper vents.
If changing the selected vent does not alter the flow of air, you likely have a blend door problem, which will require replacing the doors inside the dash that determine the direction of the air flow.
Blend doors change position when the temperature selection is changed, blocking the flow or permitting the flow of either hot or cold air.
Sometimes an AC system with a mode door problem could be working fine, but the air flow is being directed somewhere else, like back out to the engine, instead of into the car.
Want to know more about how to diagnose whether the car air conditioning filter is damaged, you can read our another article: How to diagnose whether the car air conditioning is damaged? (2)