19 March 2021
COOL JAZZ: Why your car’s air conditioning might not be working

If the air conditioning of your car is not helping you deal with the muggy Singapore heat like it should, here are some of the reasons why!

Anyone who has spent more than 24 hours in Singapore would easily come to one conclusion: the weather here is hot. Now, we’ve all had different ways of escaping this abominable heat. We’ve ducked into malls, or hid under the tiniest sliver of shade at a traffic light. For drivers, a ready relief is often the air conditioning in the car. But, what happens when the worst comes to pass, and the car simply doesn’t cool like it is supposed to?

Fret not — if you are in a real pinch and need help, AutoApp is here to lend you a hand. However, you might like to ascertain the problem your car might be facing. So, here are some of the reasons why your car might not be cooling like it should!

But first, a quick science lesson!

How your car’s A/C works

How the air conditioning system works. Source: Medium

Your car’s air conditioning consists of several components; the compressor, expansion valve, condenser and evaporator, and the refrigerant that is the key contributor to the cooler cabin temperature. These make up a highly pressurised system.

As illustrated, the refrigerant cycles through the system while converting between a liquid and gaseous state. The hot gaseous refrigerant passes into the condenser, where it condenses and becomes liquid again. The slightly cooled liquid refrigerant enters the expansion valve, where the lower pressure allows the refrigerant to cool further. The cooled refrigerant then cools the surrounding air in the evaporator, which is then channeled into the car’s cabin with the help of a fan.

Now that we roughly know how your A/C works, here are some of the ways it might fail.

Possible issues with your A/C


If your air-conditioning (A/C) is not cooling your car like it should, one problem might be the depleted refrigerant level. While the refrigerant will gradually deplete over time, leaks from the highly pressurised system are also possible. In such cases, locating the leak and replenishing the refrigerant should have your A/C working at normal levels again.


As a crucial component of your A/C system, a defective condenser can also result in subpar cooling in the car’s cabin. As the condenser is made of many seals and tubes, these parts are prone to wear and tear and can result in refrigerant leakage. The condenser could also be obstructed by physical debris caught in the front grille of the car, so give that a quick check and clear any rubbish away.


Another reason your A/C may be failing is due to a compressor malfunction. If the car interior is not as cold as anticipated, or there are noises, that might be an indication that there are problems with the compressor. In such instances, your best bet is to have it checked and repaired at a workshop.


Like every other part of your car, your A/C requires power to work. Theoretically, keeping the A/C running for long periods of time puts a strain on the engine. Luckily, the compressor clutch helps ensure the A/C does not stay running all the time and reduces the amount of power that would otherwise be wasted.

The clutch requires a full battery voltage, so a low voltage to the clutch may prevent the clutch from engaging the compressor. The clutch relay may also be an issue, but this can be checked by bypassing the relay with a jumper wire or routing the battery voltage directly to the compressor clutch.

Cooling fan

The cooling fan is part of what helps your air conditioning system remove excess heat from the engine. If the heat is not adequately removed, this will also cause the A/C to become ineffective.

If you have problems with your air conditioning, make a booking via our app and select “generic repairs”!