Why isn't the air conditioning in the car cooling?

If the air conditioning in your car has stopped cooling, cools weakly, or only works while driving, in the vast majority of cases the cause is too little refrigerant or a leak in the air conditioning system. These are two related problems responsible for most AC service requests.

Below we explain exactly what happens in the system and why it is not worth ignoring the first symptoms.

If the air conditioning in your car has stopped cooling or works noticeably weaker than before, in most cases the cause is too little refrigerant or a system leak. These are the two most common problems drivers bring to air conditioning service centers.

Too little refrigerant

The air conditioning system is not completely airtight. Each year, a few to a dozen percent of the refrigerant may naturally leak out. When its amount falls below the recommended level:

• the air conditioning cools poorly,
• warm air blows from the vents,
• the compressor turns on and off every few seconds,
• the system may not start at all.
  

It is worth remembering that the refrigerant also lubricates the compressor. Driving with a low level can lead to costly damage to this component.

Air conditioning system leak

If the air conditioning stops cooling shortly after being recharged, there is likely a leak in the system. It most often concerns:

• the condenser (air conditioning radiator),
• aluminum pipes,
• seals and service valves.

In such a situation, simply "recharging" the refrigerant does not solve the problem – the gas will escape again. Leak detection and repair are necessary.

Why not delay?

The longer the air conditioning operates with a low refrigerant level or a leak, the greater the risk of compressor damage and contamination of the entire system. Quick action helps avoid costly repairs.

If the air conditioning in your car is not cooling, it is best to start by checking for leaks and the refrigerant level. In most cases, this is where the problem lies. You can do this yourself in your garage with the help of FIXFY products! Thanks to the UV dye included in our products, you can easily locate leaks, and our 5w1 product containing a sealant will repair system losses. You can also use it preventively if you know you have a small gas loss but are not sure if and where leaks have occurred.

Other causes

Less often, the cause of the air conditioning not cooling is a damaged compressor, radiator fan failure (air conditioning then only works while driving), a faulty pressure or temperature sensor blocking system startup, as well as a clogged expansion valve or worn dryer. However, these are rare cases – in the vast majority (about 95% of cases), the problem results from a refrigerant shortage or system leak.