The Lemon IndexAC that blows warm usually has low refrigerant from a leak, or a failed compressor.
Get it checked. Fine to drive. Get it checked when convenient, and keep cool in hot weather.
A refrigerant leak (often the condenser or a line). Then: a failed AC compressor or its clutch; a blown fuse or failed relay.
Owners describe this in 2,971 complaints to the U.S. government, most often on the Honda Civic.
Cars owners report it on most
Complaints describing this symptom, by model, all years. Raw counts, not a failure rate: popular models get more complaints.
Model years that report it most
| Model year | Complaints | Share |
|---|---|---|
| 2016 Honda Civic | 88 | 8% |
| 2017 Honda Civic | 48 | 8% |
| 2007 Mazda CX-7 | 44 | 8% |
| 2014 Chevrolet Silverado | 44 | 3% |
| 2004 Honda CR-V | 38 | 8% |
| 2014 GMC Sierra | 30 | 3% |
| 2015 Chevrolet Silverado | 28 | 2% |
| 2018 Honda Civic | 27 | 4% |
| 2003 Honda CR-V | 23 | 5% |
| 2007 Toyota Camry | 23 | 0.6% |
| 2002 Honda CR-V | 18 | 3% |
| 2007 Honda CR-V | 16 | 2% |
Each row is that model year's record in NHTSA complaints, not the history of any one car. Share = complaints describing this symptom out of every complaint we hold for that model year (shown when the year has 50+ complaints).
Where it makes up the biggest share
2007 Mazda CX-7 · 8% 2016 Honda Civic · 8% 2017 Honda Civic · 8% 2004 Honda CR-V · 8% 2008 Mazda CX-7 · 7% 2020 Chevrolet Blazer · 7% 2003 Honda CR-V · 5% 2018 Honda Civic · 4%
Model years with 150+ complaints in our data and 10+ describing this symptom, ranked by share. A high share means owners of that year who complained often mentioned it.
The details
Common causes of AC blowing warm air
- A refrigerant leak (often the condenser or a line)
- A failed AC compressor or its clutch
- A blown fuse or failed relay
- A blend door stuck on heat
- A cooling fan that doesn’t switch on
General causes, not a diagnosis. A shop should confirm the cause with tests before replacing parts.
Is it safe to drive if the AC is blowing warm air?
Get it checked. Fine to drive. Get it checked when convenient, and keep cool in hot weather.
Get help right away if you smell burning when the AC is on.
Of the 2,971 complaints describing it, 0.6% mention a crash, 2% mention a fire and 0.8% report an injury.
What the complaints show
The parts owners filed these complaints under: electrical system (27%), equipment (26%), engine and engine cooling (18%), engine (13%). A complaint can list more than one.
Median odometer reading when owners reported it: 54,000 miles.
Most reports by make: Honda (521), Chevrolet (439), Ford (379), Dodge (192), Gmc (169).
What owners say it cost to fix
Repair bills owners named in complaints that describe this symptom (a/c & heat repairs): the middle half ran $750 to $2,000, typical $1,200, from 202 bills.
Each figure is one repair bill as an owner wrote it in a complaint, not a quote for your car. Prices vary with the part, the shop and the year.
Related symptoms
Car heater not working Engine overheating Water leaking inside car Mold or musty smell in car Sunroof shattered Fuel gauge not working
Quick answers
What causes AC blowing warm air?
AC that blows warm usually has low refrigerant from a leak, or a failed compressor. Common causes: a refrigerant leak (often the condenser or a line); a failed AC compressor or its clutch; a blown fuse or failed relay; a blend door stuck on heat; a cooling fan that doesn’t switch on.
Is it safe to drive if the AC is blowing warm air?
Get it checked. Fine to drive. Get it checked when convenient, and keep cool in hot weather.
Which cars have this problem most?
In complaints to NHTSA, owners describe it most on the Honda Civic, Honda CR-V and Chevrolet Silverado. These are raw counts, so popular models rank higher; complaints are owner reports, not proof of a defect.
How much does it cost to fix?
In 202 repair bills owners named in complaints describing it, the middle half ran $750 to $2,000. The right repair depends on the cause.
Counts: NHTSA owner complaints whose text describes this symptom (we matched owners' own wording, then read samples to check the matches). A complaint is an owner's report, not a diagnosis or proof of a defect. Causes and advice are general information in our own words, not repair advice for your car. Every symptom · Engine code lookup