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Q: Weird smell from AC.

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My air conditioner has a foul smell coming out of it.

There is usually only two causes of this symptom. Inside your dash lies the evaporator for the air conditioning system. This evaporator looks like a small radiator but gets cold instead of hot. Imagine a soda can freshly opened out of the refrigerator and then placed on hot asphalt on a one hundred degree day. The can will start to sweat and that is exactly what the evaporator does in the heat of your interior on a summer day. A drain system for the evaporator is usually equipped and if the drain tubes become clogged with debris of any kind, they will not drain. The lack of draining will cause a fungus or bacteria to grow inside the dash on the evaporator. This fungus is what causes the smell. The first step would be to find the drain tube and clean it out if necessary. Once done you can spray some Lysol into your air duct under your windshield wipers where the air is sucked in from the outside. This may kill the bacteria and prevent any more from growing. If this does not work, replace the evaporator. A much simpler cause would be a clogged cabin air filter. Have this inspected by a certified technician before anything else and replace any components as needed.

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