Q: Air conditioner blows warm air.

asked by on November 18, 2016

Got in my truck today. Warm air only blows when I turn it on. This is both idle and driving. Blower motor is new. Recharged the system about three months ago without problem. Was super cold. There was an odd smell coming from my vents over this week. Don't know if it was freon or not. Condenser fan motor is two years old. Lines are not cold when hood is popped. No signs of sweat, condensation. Something is wrong, but I cannot pinpoint what it is. I'm a big diy kind of guy. I can't do it myself if I don't know what it is. Please help. Thanks

My car has 146000 miles.
My car has an automatic transmission.

The most common cause for warm air when the air conditioner is commanded on is a low refrigerant charge, usually from a leak. One way to check the charge is to have a technician attach a manifold gauge set and inspect the system pressure on the high and low sides. The a/c compressor will not be running so pressures should be equal on both sides, but if the pressure in the system is very low then there is a leak. If the system charge is about normal, the a/c compressor clutch may not be working. The clutch turns on and allows the a/c compressor to spin while the engine is running and no function from the compressor will allow warm air to come out of the vent. Consider hiring an experienced technician like one from YourMechanic who can come out and perform an a/c system check and diagnose your air conditioning concerns more personally.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

No cold air from AC

If the AC is only blowing hot air then most of the time it is because the AC compressor is not turning on. The compressor will not turn on for a number of reasons, but the most common is low...

After doing a head gasket on a 2002 3.9 Dakota, how long will it take after starting it will it take to start to run normally?

Unless your repair involved replacement or modification of engine controls, such as the IAC valve or throttle position sensor, the instant you start the truck after replacing just a, or both, head gaskets, the engine should operate normally. If the...

how many serpentine belts does a 2005 Dodge Stratus have

Hey there. Your Dodge Stratus should have two main belts. One that runs the power steering pump and one that runs everything else (i.e. crankshaft, alternator, A/C). If you need help with a serpentine belt replacement, a certified technician from...

Related articles

How Long Does an AC Compressor Belt Last?
For For the air conditioning system in your car to work properly, it has to pressurize refrigerant. That is the function of the AC compressor. The compressor itself gets a signal from the AC relay, and is operated by a...
How to Replace an Air Conditioner Receiver Drier
The AC receiver/drier is stores and dries refrigerant. This component should be replaced if too much water enters the system or if leaks are found.
Industry News for Automotive Techs: November 5 - November 11
Tesla buys Grohmann Engineering, Ferrari's future hybrids, next-gen Dodge Charger and Challenger, Nissan e-Power system, and YourMechanic recognition.