Having an air conditioner that doesn’t blow cold air is frustrating on a hot summer day. Learn how to diagnose and repair a car with this problem in a few steps
The problem could be a clogged filter, a faulty A/C compressor, or a refrigerant leak. So instead of putting up with an uncomfortable car, diagnose the problem and find a solution for your customer. Let’s take a look at the easiest way to diagnose a car air conditioner blowing warm air so you can fix it properly.
The car uses cooling fans to blow cool air into the passenger compartment. If your air conditioner is set to maximum and the fan is running at high speed, but the air is moderately cool, the cooling fan may be the culprit.
How to diagnose a faulty condenser fan? The condenser fan starts rotating as soon as the air conditioner is turned on. Place this fan under the hood as it is next to the radiator fan. Then have someone turn on the air conditioner and watch it start spinning.
If it doesn’t start spinning, you may need to determine the cause, as it could be a faulty fan relay, a blown fuse, a faulty temperature sensor, faulty wiring, or the ECU is not commanding to start.
To fix, you need to troubleshoot the issue based on the cause. For example, a blown fuse or a wiring problem should be easy to fix at home. Also, you may need to replace a faulty temperature sensor, as it can prevent the fan from starting if it doesn’t send a turn-on message to the ECU.
An auto mechanic can identify and fix all of these problems, and most condenser fan problems won’t cost more than a few hundred dollars to fix.
The radiator fan turns on and off when the engine warms up or is idling. Some symptoms of a malfunctioning radiator fan include:
Diagnosis by detecting the heatsink fan on the heatsink. Then start the car and let it warm up. Then look to see if the radiator fan starts spinning as the car warms up. A radiator fan that is not spinning could be a problem with the fan itself or its motor.
To fix this, it’s best to have a technician look at the radiator fan to determine the cause of the problem. A replacement radiator fan costs $550 to $650, while the radiator fan itself costs $400 to $450.
Your car’s air conditioner uses a compressor to circulate air. If the compressor is broken, the refrigerant will not flow and the air conditioner will not produce cold air.
After determining that the problem with an air conditioner blowing warm air is a broken air compressor, it is best to replace it. When replacing, consider replacing o-rings, batteries, and expansion devices.
The air conditioning system must be filled with refrigerant to function properly. This refrigerant starts as a gas on the low pressure side and turns into a liquid on the high pressure side. It is this process that keeps the cabin cool when the air conditioner is on.
Time to recharge the system, especially if you haven’t done so in the past six or seven years. Unfortunately, owners cannot charge the air conditioner at home because the refrigerant must be properly disposed of by a licensed professional. If the cause of the low refrigerant level is a leak in the system, also check it for leaks.
AC filters remove pollutants from the air entering your vehicle’s air conditioning system. It removes impurities, allergens and pollutants that make the interior uncomfortable.
Over time, cabin filters can become dirty and clogged. When it is too dirty, it may show symptoms such as:
To fix, there is no other way to fix a clogged or dirty air filter other than replacing it. The standard particulate filter needs to be changed every 50,000 km, and the activated carbon cabin filter should be changed every 25,000 km or annually.
If your car’s air conditioner isn’t blowing cold air, fixing the problem isn’t always easy. Remember that you can always check your car owner’s manual.
Post time: Mar-07-2023