Why is my car AC not blowing cold?

Top reason by a mile: low refrigerant from a slow leak somewhere in the system. AC refrigerant doesn't 'use up' — if it's low, it leaked out, and just topping it off only buys you a season. Other causes: bad AC compressor (you'll hear it not engage), clogged cabin air filter (blows weakly cold), failed blend door actuator (clicking from behind the dash), or a blown AC fuse.

Get a free AI-ranked diagnosis for your exact year, make and model — with fair repair cost ranges and DIY-vs-shop guidance.