This has happened every summer for two years now. After about a 2 to 8 hour drive, the AC will literally just stop working randomly or very weakly, and this is always accompanied with the blower fans becoming significantly weaker and louder. If I turn the car off for an hour in some shade, it will work again normally, though the issue goes inevitably come back.


Im assuming a relay is going out, or perhaps something about the AC such as oil, but it only ever does this in the thick of summer after a long drive thats over 2 to 6 hours, and never in spring, or fall.


Im not sure how applicable this is too, but very rarely when I start the care, the Battery light for the 12v comes one, and hence the 12v isnt being charged. After a few on and offs the issue seems to resolve itself, along with a 12v disconnect, though I think these two may be related. This rarely happens and has only happened some 3 times total in the 4 years I have had this car.

 

Check back in 10 months. See if it's still happening.

 

This sounds like the sort of issue that will eventually need the attention of a mechanic, and might end up with them replacing part after part while searching for a failure condition they cannot replicate in the shop.

Before biting that bullet, check that all the electrical connections involved are good (tight, no corrosion, no melted connectors), especially any relevant grounds. Also be sure the condenser allows good air flow (not packed up with leaves or mud) and that the condenser fan runs. If none of that turns up an obvious problem then have an AC shop have a look at it. If the refrigerant is contaminated or is low they should be able to fix that for not too much $$$.