Smelly air conditioner

My girlfriend has a 2007 Prius that often has a strong ammonia smell coming from the air conditioner. After talking to the dealer’s maintenance guys, I replaced the cabin filter and the engine filter. But the smell still wont go away. Any ideas out there? We are tired of choosing between the heat and the cat pee smell.

No one mentioned spraying a anti-bacterial agent into the evaporator housing (introduced at the base of the windshield or inside the car at the recirculation intake?) considere it mentioned. Some people like Lysol,I like a product sold at GM Dealerships,works very good. For further reading use “search” this topic has been covered extensivly.

Ammonia smell and not mildew smell? Sounds like someone or some critter may have relieved themself in the air inlet at the base of the windshield. Can you smell it there? Flush thoroughly with soap and garden hose and see if that helps.

If it is more like mildew, then there is also a product from Wurth that you can buy from the on-line vendors that sell specialty car detailing products. It worked well for me on a couple of my cars.

Lots of microorganisms produce ammonia. Start with the easy stuff, make sure you are leaving the AC system in an “open position” when you park it. The owner manual usually advises this, any position except MAX/RECIRCULATE or OFF. Make sure the drain is clear. If this does not help. Post back for more suggestions.