Q. My A/C was recharged several weeks ago and ran well until one afternoon, when it was only blowing warm air. It blows warm air even when it is cool outside. I need to know what it could be before going to the mechanic. A. By far, the most common cause would be a slow leak in the system and Freon might have been lost causing warm air to blow. There also can be lots of other possibilities. Try going back to the shop where the care was done or a different one to see what they find. Air conditioning work requires lots of equipment and is not really a do-it-yourself repair. Simply recharging an A/C system never fixes anything. An electrical problem may have occurred if there is a leak. The system has three major components and a few smaller ones. Most of the time, your problem lies in at least one of the three big ones: compressor, evaporator, and condenser. It also has a small metal can, containing desiccant, which should be changed whenever the system is opened. The components are in different locations in the car, so there really is no such thing as replacing the whole air conditioner as many people think they have after a major repair. Depending on the vehicle, there are several feet of hard and flexible lines that can become damaged can cause a leak. The best thing to do now is to have it evacuated and recharged with the addition of dye to aid in finding the leak in the very near future. If do not wish to go to the dealership, find a reputable AC specialty shop or independent garage that does full-service AC work. Finding leaks in AC systems these days is not hard since there are high-tech leak detection tools. Good AC shops will even show where the test equipment is detecting the leak. Most shops use either a “sniffer” or a special dye that shows up under backlight.

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