Why does My Aircon Not Blowing Cold Air

It is normal for the car air conditioner to blow cold air, but what if your car air conditioner not blowing cold air anymore but instead it blows warm air? If this is the case then there is a problem with your car air conditioning system, however, this may not also always indicate a problem.

How to determine if the car air conditioning is running under normal condition?

(1) If the car air conditioning vents blow warm air when the car engine is hot or under a lot of stress, it means that the car is equipped with a safety feature that shuts off the compressor. Most cars have a device that temporarily disengages the compressor of the car air conditioning when an engine is under a lot of stress or when the engine is extremely hot and this is normal.

The reason why car AC is not blowing cold air anymore

1. Slow refrigerant leak.
2. Clogged condenser.
3. Expansion valve freezes up
4. Failing air conditioning compressor
5. Car air conditioning electrical problem

AC Car troubleshooting

A liquid substance is known as "refrigerant" is the lifeblood of an A/C system. Loosely, it's a refrigerant which carries the heat from the passenger compartment to the outside of the vehicle, thus making the passenger compartment cooler. However, refrigerant often slowly leaks out of a hose or seal. In time, this results in a steady reduction of the cold air produced by the A/C system.

The other possibility in this scenario is that the condenser is clogged. The condenser is the part of the A/C system that's responsible for removing the heat which the refrigerant absorbs from the passenger compartment. It's essentially a mini-radiator that's mounted in front of the regular radiator. In time, the condenser can gradually become clogged with dirt/debris/bugs. This will result in a steady reduction of the cold air produced. The main cause of this problem is likely a refrigerant leak. A clogged condenser (if at all) would only be a contributing factor here.

What to do?

First, check the condenser for dirt/debris/bug buildup and clean if necessary with a soft brush and water. This may improve the problem. If not, you'll need to take this vehicle to a garage and ask the mechanic to "charge" the A/C system (i.e. add refrigerant). Also, ask him to locate and repair the leak. The refrigerant R-12 (also known as "Freon") is extremely expensive. Why? Because, its production was banned beginning January 1, 1996, and therefore all that remains is the Freon produced before this date (i.e. it's a dwindling supply). Therefore, expect to pay a premium to have your A/C charged (often $50.00 - $150.00).

But, if car ac vents blow out warm air even when the engine is not under a lot of stress or the engine is within the operating temperature then that’s a different story and this means a problem. With this kind of condition, it indicates a problem, which is more often depend on how the air conditioning functions. If the ac vents initially blow out cold air then after quite a while it starts to blow warm air the problem is freezing up the expansion valve.

If an air conditioning expansion valve freezes up, the flow of refrigerant to the air conditioning lines will be blocked temporarily which can cause the AC vents to blow out cold air initially then afterward begins to blow out warm air. The expansion valve can only be freezing up if there is moisture on the refrigerant and this moisture can only be entering via a leak on your car air conditioning system.

If the car AC vents blow out warm air in a random order then this suggests that the problem is a failing compressor or an AC electrical problem. During the failure of the compressor, the refrigerant will stop flowing during the downtime thus causing the air conditioning vents to blows warm air sometimes.

If there is a car air conditioning electrical problem -usually an air conditioning wire is loose- it affects the air conditioning components and will stop working during the time when a wire lost contact of if the circuit is broken, consequently the car AC blows out warm air.

What to do?

Bring the car to a reputable repair shop specializing in car air conditioning system. If the problem is about the Expansion valve freezes up, ask the mechanic to locate the leak that causes the moisture to enter into the system and mixed it up with the refrigerant.

However, if that is not the problem then ask the mechanic to inspect your car air conditioning compressor and car air conditioning electrical wiring.