Air conditioner not cold in car for sale

Air conditioning not cold in car

Car Air Conditioning / September 23, 2018

Need to fix your car's air conditioner? We are a team of ASE certified mechanics that have created this guide for you so you can understand how the system works and what to look for when it doesn't. We also have included popular repair guides with videos which will help you stream line your repairs or see what you are paying for when taking your car in to a repair shop. Let's jump right in!


When looking under the hood at your car's air-conditioner it might seem complicated but it's not. Once you know how it delivers cold air you will see it's really quite simple. Your heater and air conditioner (HVAC) does three jobs; cool the interior of the car, heat the interior up and defrost the windshield. All three modes work together as a complete system. The climate control system is controlled by a main computer which houses the controls for the system and sits in the dash in most cases. This computer gives commands to the compressor to start pressurizing the refrigerant along with the blend door actuators which direct air flow from the floor, mid and defrost vents. These air door actuators also control air temperature by mixing the hot air from the heater and the cold air from the AC. When one part of the system fails to operate like the air conditioner then one part of the system stops working in this case the cold air. The AC system has four basic parts: A compressor, which is powered by the engine using a serpentine belt. On hybrid cars the compressor is electrically powered and does the same operation. A condenser which is located in front of the engine radiator and cools the refrigerant from the compressor before it heads to the evaporator located inside the vehicle. This is where the high pressure liquid is released into the evaporator as a low pressure gas and where the coldness is created. The blower motor then circulates the air throughout the interior. Before you start doing repairs on the system it's a good idea to see how the a/c system works.

Before You Begin

Start with the car on level ground with the transmission is park and the emergency brake set. The engine should be off, but warm. Wear safety goggles and gloves to protect against injuries. Never loosen or undo any hoses or fitting before discharging the system of refrigerant. The system does contain a slight amount of oil which can be expelled while discharging. You will see tools and supplies used in the following guides that you will be able to find throughout and at the end of this article, also a list of specific repair manuals. One thing to remember is all air conditioner systems work on the same principle. Okay, now that you have had a crash course on how the system works let's approach this problem like a mechanic would.

Why Isn't My Air Conditioner Working?

If air is not blowing from the vents it is not the problem of the refrigerant recycling system (A/C) and can be attributed to the blower motor or a vent control actuator. Here is how to tell which; start the engine and turn the air conditioner on. Next, move the fan setting from the highest to the lowest. If you can hear nothing it is a problem with the blower fan. If you can hear the fan but no air is forced through the vents, or if the air is being generated from the wrong vents this is an actuator problem. If air is blowing from the correct vents but is not cool (no cold air - blowing warm air) continue down the guide. When the air conditioner is switched on three things begin to happens, the compressor, blower motor and vent actuators all receive an electrical signal to turn on. This causes the compressor clutch to engage while working the internal parts of the compressor pump. This pumping action compresses the refrigerant so it can circulate around the system. The following step are presented in order of popularity.