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.

AC is not working Inspection $111.46 - $131.46 Get a Quote

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.

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


Experienced Mechanic?

Earn up to $70/hr

What others are asking

What should I do with the air bags after they have deployed?
When an air bag has deployed, it will need to be replaced. After an accident in which the air bags have been deployed, get your vehicle serviced immediately. Tip Even if your air bags did not deploy, you should have...
No power after startup
It sounds like your catalytic converters are stopped up. This is a common issue with fords. If you have an infrared laser temperature gun, you could aim it at your tailpipes while someone else revs the engine. If the catalytic...
Car overheating after oil change
There is very little chance that having the oil changed could be causing your car to overheat. Most likely, it is just a coincidence. I would ask for help from one of the mechanics at YourMechanic. They can come to...
Engine idles rough and jumps between 500 and 1200RPM when shift from Drive to Reverse; Check engine light on
You may have a couple of separate issues: The flashing Check Engine Light under heavy load is most likely an ignition system misfire (https://www.yourmechanic.com/article/how-can-problems-with-the-ignition-system-cause-misfiring_2). This could be something like a coil pack or worn spark plugs. These engines are known...
ABS runs key out
The ABS pump is fed power directly from a fusible link and not the 10A brake fuse. If the pump is running non-stop, this is an indication of a faulty brake pressure modulator valve unit that will need to be...
The Check Engine Light came up with the code P2017, what do I need to replace?
If you are getting this code it is due to one of two things. The vast majority of the time it is caused by a failure in the variable charge motion actuator, which is the same part that you mentioned....
My clutch is not working Entire clutch repair or clutch master cylinder repair? How do I check the cylinder?
Hi there. Check the slave cylinder to the clutch and see if the piston is all the way out. If the piston is all the way out or its not touching the clutch fork, then the release bearing has broken...
now truck just starts and dies
Starting and stalling can be caused by a number of reasons. If the vehicle is equipped with a factory anti-theft system, there could be issues with that system. Mechanical issues such as a vacuum leak can also cause stalling. If...
My car loses power then won't go over 20 mph its a 05 pontonic grand prix
Hi April. The Reduced Power light usually indicates a fairly serious problem with the throttle system. When this light illuminates the vehicle will often go into a “safe mode”, which will severely limit the speed of the car and in...

Related articles

Why Won't My AC Blow Cold Air?
When you turn on the air conditioner in your car, you expect to receive a flow of fresh, cold air....
How Long Does an AC Control Switch Last?
Every Every year, vehicles become more and more complex, with computer components replacing mechanical parts. This is very apparent in your car’s air conditioning system, which relies on an AC control module to deliver the ideal heating and air conditioning...
How Long Does an AC Low Pressure Hose Last?
Your Your car’s air conditioning system consists of a number of components, including an evaporator, condenser, dryer and compressor. The system itself works by means of a refrigerant, which is carried to, and taken away from, the various components, by...