When moisture gets into your car's air conditioning system, mould can start to grow. This is bad for your health and bad for your vehicle, so visit your local service station or mechanic if you notice one or more of the following four signs.
1. Unpleasant Odours
If you've ever found mould growing in your home, you'll already know how bad it can smell. There's generally a musty, sickening aroma, and that unpleasant smell becomes even more pronounced when mould grows in the relatively compact interior of a car. If mould is present, unpleasant aromas will increase as time goes by, and you'll find things particularly pungent when you turn on the AC system.
2. Unclean Vents
If you think your air conditioning system might be harbouring mould, try taking off one of the vents and looking at the back. Mould will often grow in the darkest, deepest parts of your air conditioning system, but some can migrate up towards the passenger compartment. If you find a patchy black residue that won't wipe off easily, you can bet there's more mould further down the system.
3. Signs of Illness or Allergies
Mould can damage your health as well as your car's health, and you may begin to notice signs this is happening. After all, turning on the air conditioning will mean blowing mould spores directly into your face. If there's mould in your car, you may start sneezing, coughing, or wheezing without explanation. You may also feel drowsy while driving, experience tightness across your chest or feel irritation around your eyes.
If these symptoms only tend to present themselves while you're driving and just after you've left the car, mould growth is the likely culprit. Sneezing and coughing might not sound like a big deal, but exposure to mould can cause serious health issues, so don't ignore any physiological symptoms.
4. No Water Runoff
When you run the air conditioning for a while, water should be draining under the car – you'll generally only notice this when you move your car a little after parking for some time.
Water runoff might sound like a bad thing, but it's actually a sign your car's air conditioning system is in good condition. If you don't see any water, it's likely the drain hole is plugged and the evaporator isn't drying out. Mould growth could be preventing water from draining away, and that in turns makes it easier for more mould to grow. In some cases, water will eventually start pooling in the vehicle itself. For more information on your car air conditioning system, contact your local auto service.