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Q: My ac only blows cold air when I'm driving fast

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My ac hasn't worked for over a year Now. I brought it in to get serviced and I was told that my wires were melted and that's why it stopped working so I had them replaced and after the ac was Back to normal, for 2 weeks. Now unless I have it only on a low setting and driving at 45mph is the only time it BARLEY blows out cold air. It also works great at night when it is cooler out its freezing and seems like it blows out a little stronger (I live in Florida). My alternator just died too I don't know if that could have been a part of it and that is getting replaced this week, I know how it expensive it is to get AC replaced so I'm hoping this could be a quick easy fix? I have a new born baby coming in 2 months and really need this problem fixed.

My car has 120000 miles.
My car has an automatic transmission.

When your car is moving, say at 45 MPH, there is lots of air flow over the condenser (the condenser is the heat exchanger in front of the radiator) and that airflow is essential to proper a/c system operation. To maintain good airflow when the car is in stop and go traffic, or is completely stopped, condenser fans will come on automatically. If the fans do not come on, the circumstance you have described with poor cooling could occur. You might also have a low state of refrigerant charge. Other possibilities are that the compressor clutch is not cycling as intended or that the condenser might be blocked or dirty. And, of course, you could have a combination of these issues. To get the a/c issue resolved, the best thing to do is request an air conditioning system inspection. The responding certified mechanic will come to your location, pinpoint the fault and get this resolved for you. Once diagnosed, the mechanic will be in a position to give you a repair strategy to get the A/C system fully functioning and he or she will estimate the cost of the required repair. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

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