Diagnosing A/C Car Problems: Top Things That Can Go Wrong and How to Fix Them

It’s hot out there and it seems like everyone has been talking about how hot it’s been lately. The thing is, in Australia, it’s pretty much always hot. And if you drive a car with no air conditioning then you know just how hard it can be to drive with the windows down and still feel like you’re not going to die of heat exhaustion.

But what do you do if your car’s air conditioning isn’t working as well as it used to? Or maybe it doesn’t work at all? Don’t worry, we’ve got you covered. Here’s how to diagnose the problem with your car’s air conditioning system and then repair it yourself. 

First things first: before you start doing any kind of work on your car, it’s important that you know which kind of system you have. If you have a Heating and Cooling (HVAC) system then this guide will be able to help you out. The process for diagnosing and repairing a cooling system is pretty much the same no matter what type of vehicle you have, and you’ll be able to find replacement parts in any automotive parts store. I prefers hopping from an online automotive parts store, as there are more options and parts available for any type of vehicle.

Steps to Diagnosing A/C Problems in Your Car

Here are the steps you’ll need to take:

1. Turn on the car and let it run for about 10 minutes. This will give you a good idea of how hot the engine is running and whether or not there are any issues with coolant leaks. If the temperature gauge isn’t in the middle then that’s your first indicator that something might be wrong with the air conditioning system.
2. Once the car has cooled down, pop the hood and check out the condenser. The condenser is what pulls heat from the air conditioning system and sends it to the radiator, which then cools it down. If you see any signs of coolant leaking onto or into the condenser (like rust or discolouration) then that’s a big problem and your car’s air conditioner needs to be professionally diagnosed immediately.
3. Check out the fins on the condenser. They should be straight and not bent or broken in any way. If they’re damaged then you’ll need to replace the whole thing. If you’re not sure which one is the condenser, check out our guide to car air conditioning parts here.
4. Next up: take a look at the evaporator and heater core. These are both located under the passenger side of the dashboard. The evaporator should be intact with no signs of damage or rust. If it’s damaged then you’ll need to replace it immediately because the coolant can leak out and cause some serious problems for your vehicle’s interior.
5. Check out the heater core next, which is located in front of the evaporator. The fins on the core should be straight and not bent or broken. If they are then you’ll need to replace it because coolant can leak out from there as well. You’ll also want to make sure that there aren’t any signs of rust or discolouration on the hoses or anywhere else in this area.
6. If you don’t have a scanner, then you’ll need to check the air conditioning temperature gauge on your dashboard. Turn on the car and let it run for about 10 minutes again, then turn off the engine and take a look at the gauge. If it’s in the middle then that means that your system is working properly. If not, then there’s something wrong with your cooling system – which brings us to step 7…
7. Next up: listen to the sounds of your car. Open the hood and put your ear near the engine block. You’ll want to listen for any strange noises coming from the air conditioning system or anything else in your car. If you hear anything unusual then you know that there are issues with the cooling system and they need to be diagnosed by a professional right away.
8. Take a look at the compressor next. The compressor is what works to pump coolant through the system and keep everything working properly. Check out the fins on it, which should be straight and not bent or broken. If they’re damaged then you’ll need to replace the whole thing. You should also check out the belts and hoses in this area, which are located behind and around the compressor.
9. Next up: look at the condenser fan. The condenser fan is what helps push air through the system, so if it’s not working properly then that means your car’s air conditioning doesn’t work as well. Check out the fins on the fan, which should be straight and not bent or broken. If they’re damaged then you’ll need to replace the whole thing. You should also check out the belts and hoses in this area, which are located behind and around the compressor.
10. Lastly, check out the evaporator. The evaporator is what sucks coolant through the system and pumps it around so that it can cool everything down properly. The fins on the evaporator should be straight and not bent or broken. If they’re damaged then you’ll need to replace the whole thing.