Recently on a 3 hour drive the AC stopped blowing cold. Since then for normal daily driving the AC system is working fine.
My car has 40000 miles.
My car has an automatic transmission.
When you were on a long trip the A/C could of had a problem with a relay or cycling switch stuck and causing the A/C to either not cycle out and freeze the evaporator till air flow stopped getting through the evaporator. You would of noticed the air flow being very low and not cold. If the relay or cycling switch cycled out then would not cycle back in then you would just have outside air blowing through as if you turned off the compressor your self. You should have a mechanic check the A/C performance to see if system is low on refrigerant, and look at the cycling switch and relay if it is functioning properly. The mechanic would need to verify the problem you had to properly diagnose the problem.
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