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Q: A/C and heat work intermittently

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Some times the A/C or heat will blow and the next time there won't be any air flow at all. Fuse is not blown, before I go tearing the dash out, I'd like to get more knowledge on the exact problem, thank you!

My car has 142000 miles.
My car has an automatic transmission.

Hello - I would first check for fan motor voltage coming out of the HVAC control switch. A bad contact for the fan could act as you describe. If you are consistently getting 12 volts out of the switch TO the fan motor, an electrical fault with the fan motor (worn brushes or dirty commutator on the fan motor) is the next component to check. I would recommend having a Fan Speed Control is Not Working Inspection completed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.

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