My AC does not always work. If I fiddle with the blower knob I can ususally get it to work on the lowest setting.
My car has 104000 miles.
My
It sounds like you may have a faulty blower motor resistor. The highest speed setting may still work because in most cars in the highest fan speed settings the current bypasses the blower motor resistor. In some cars, if the resistor is failed, the fan may stop working completely. Another reason a blower motor resistor may fail is when the blower motor has a mechanical problem or when a foreign object jams the blower motor fan blade and prevents it from spinning freely. This leads to increased current through the resistor and causes it to overheat and fail. I would suggest having an expert from YourMechanic come to your location to diagnose your system to determine what may be causing the fan not to work properly.
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Here is why; Dirty filter: A dirty filter limits airflow through the system, eventually straining your AC and making it blow warm air. Clogged/dirty outside AC unit: Both the outdoor and indoor AC units work together to supply cool air during summer.
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It sounds like you may have a faulty blower motor resistor. The highest speed setting may still work because in most cars in the highest fan speed settings the current bypasses the blower motor resistor. In some cars, if the resistor is failed, the fan may stop working completely. Another reason a blower motor resistor may fail is when the blower motor has a mechanical problem or when a foreign object jams the blower motor fan blade and prevents it from spinning freely. This leads to increased current through the resistor and causes it to overheat and fail. I would suggest having an expert from YourMechanic come to your location to diagnose your system to determine what may be causing the fan not to work properly.
With regard to the A/C system, if gauge pressures (high and low) are normal when the system does operate, there are really only two principle possibilities for intermittent operation. One is circulating moisture in the system (due to a saturated dryer) which periodically freezes (and thaws) at the expansion valve and the other is a failure in the A/C control system, that is the clutch, sensors, and other electronics that control the compressor cycling. The cause of the problem can be readily found if you request an A/C system diagnostic. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.