Skip to Content

Car Air Conditioner Smells Like Urine? Here’s How To Fix It

Car Air Conditioner Smells Like Urine? Here’s How To Fix It

Yes, today’s car air conditioners are a lot savvy and fancier than before, the main elements used are still the same as developed by the engineers long ago.

Irrespective of the car brand or model, every car air conditioner comprises an evaporator, a compressor, a condenser, etc.

Out of these, an evaporator is the nearest to the air vents and the principal component at fault if the AC system isn’t working well.

Now, as the car nears its age, its air conditioning unit stars accumulating bacteria, mold, fungi, and other microorganisms due to favorable breeding conditions.

These develop & multiply themselves over time. After a specific time, these start to affect the air conditioner’s working in one or more ways. One of them is the smell of the air coming out from the vents.

If you don’t maintain your air conditioning system, all these bacteria can give rise to weird smells like those coming from rotten eggs, pee, drainage, etc.

If the bacteria growth is not much, you will hardly notice the smell. However, if the bacteria growth is allowed to continue without control, you will start feeling these unpleasant & irritating smells.

In today’s article, we’ll discuss the significant causes behind the car’s air conditioner’s urine-like smell and methods to eradicate it. So, let’s start without further ado. 

Why does your car’s air conditioner smell like urine?

Your car air conditioner smells like urine because it may have developed certain categories of bacteria, mold, fungi, and other microorganisms. Out of these, mold is the reason why the air conditioner smells like urine.

Your car’s air conditioning system is made such as it requires timely servicing. Otherwise, it will start incurring problems.

For example, the air conditioner will either work inefficiently, consume more power, or dissipate different odors.

There are multiple reasons behind the same. With age, the car’s air conditioning system develops certain categories of bacteria, mold, fungi, and other microorganisms. Out of these, mold is the reason why the air conditioner smells like urine.

A mold is a highly toxic type of fungus that multiplies rapidly, and you can find it everywhere. Damp weather conditions are what contribute to the multiplication of molds.

Hence, if you often park your car in damp conditions, mold can start developing. In some cases, these molds affect the car’s conditioner and give out Mycotoxins or byproducts.

These byproducts are more dangerous than the molds themselves and responsible for emitting a smell like ammonia.

Since ammonia is a primary urine component, you assume the smell is that of urine. There is another reason why molds can develop in your car’s AC system.

As said initially, the evaporator is the most critical component of your car’s air conditioning system.

The evaporator is responsible for eliminating any moisture from the air that the evaporator is cooling and throwing out from the air vents.

This moisture is either given out from the car through the drain hole or dissipates in the air. However, in some instances, the same moisture could not go away and leads to mold accumulation.

Ways to get rid of urine smell from the car air conditioner

Now that you know that mold accumulation is the chief reason behind the urine-like smell from your car’s air conditioning system, let’s fix the same.

For this, there are multiple ways, from easy to challenging yet more effective. Continue reading to know more about this.

Check whether the condenser is dripping water out or not

If the air conditioner drain line is plugged or choked, the moisture removed from the evaporator’s cool air won’t drain out of the car.

It, in turn, will lead to the growth of molds and subsequent urine-like smells. To remove this, turn on the car with its air conditioning system and let it idle for 5-10 minutes.

Suppose you notice the drain line dripping the water out on the ground, the better.

However, if it’s not happening, you will have to detach the AC unit’s drain line, clean it, and attach it again. Now, the AC should start working like new. 

Clean the entire ventilation system with any disinfectant

Your second quick fix involves cleaning the entire ventilation system with a car-based disinfectant. To begin with,

  1. Open all the windows.
  2. Please turn on the car, then the AC, open all its air vents, and keep the fan at its highest level. Remember to turn off the recirculation mode of the AC.
  3. Take the disinfectant and spray it evenly over both the air intake vents while both the AC and car are in the ON state. The air intake vents are present on the bottom of the windshield and are usually two in number—one on the passenger and driver sides.
  4. Keep the air conditioning system on for another 5-10 minutes to allow the disinfectant to circulate through the system and vents. 
  5. Once again, check the air conditioning system and look for the urine-like smell. If everything’s okay, you’re good to go. Else, spray some more disinfectant and check. 

Remove the evaporator and clean it

If the first two methods don’t yield the desired results, your last resort is removing the evaporator and thoroughly cleaning it.

It’s a bit difficult for you to undertake this responsibility. Hence, it would help if you immediately headed to any nearby mechanic. 

Invest in regular maintenance of the car’s air conditioning system

If you don’t want to experience your air conditioning smelling like urine, you should ensure the car’s air conditioning system’s timely maintenance. It involves doing away with any clogging of the drainpipe, clogged-up air filter, etc. 

So, these are the most common ways of eradicating the foul odors from your car’s air conditioner. 


With age, your car’s air conditioning system begins to develop specific categories of bacteria, mold, fungi, and other microorganisms.

All these tend to affect the air conditioner’s working in one or more ways, the most common of which is the production of unpleasant smells like that coming from rotten eggs, urine, drainage, etc.

While in some cases, these smells go unnoticed, other cases may involve intensified smells.

Hence, you should check what all lead to these smells in which the accumulation of molds tops the list. Still, there’s nothing to worry about, and the above methods can make your car smell fresh again.