My car's AC is emitting a mildewy smell. How do I get rid of it?

One thing to check is that the natural condensation from A/C is Draining.

The A/C cooler is inside a box which all the vents connect to.

That box has a Drain in the bottom of it,,,connected to a hose which exits beneath the car.

Occasionally that Drain will get plugged up,,and the box fills with water.

As you can imagine,,,thats makes Ideal conditions for Mold and Mildew.

If that drain IS plugged,,,,NOTHING will ever get rid of the mildew smell because it's constantly growing new mildew.

Some cars are very obvious and easy to find & clear the drain,,,others are rather difficult

Find somebody who is Well familiar with Your Make & Model car,,,and ASK Where & How-To clean the Drain,,

Or get a shop to do it----it should not be expensive at all.

However You get it checked/fixed,,,It's IMPORTANT to do so.

Very Very Often the a/c box will "overflow",,,and that water gets into the car.

The way Carpet and Padding and floor insulation is done in most cars,,,,

It can hold a LOT of water before You ever realize the carpets are soaked.

It makes a terrible mess,,,and a LOT more Mildew IN / Under the Carpets,,,

and it's a lot harder to deal with that than just the drain itself.

If the Smell in the Car is rather faint or mild,,,

but it seems Concentrated,,or Stronger Smelling directly from the VENT,,,

Odds are good You have a stopped up A/C drain.

You can look under the car whil A/C is ON and car's running---Water should be Dripping/Draining out onto the ground in about the Middle of the car.

Most Drains are position about Inline with Windshield---they are mounted between Engine & Passenger compartment.

Good Luck

Any and everywhere try Lysol on the carpet first in a little patch to make sure it wont alter the color of your interior or laundry soap and a shop-vac and fa-breeze does wonders also and if that doesn't work sometimes its in your vents they have something at the parts store that cleans out your air vents I don't remember what it's called but I'm sure if you ask an employee they should be able to help you out. If you can't tell I've had the same problem before I had a leak in my trunk and every time it rained my back seat would fill up with a few inches of water.

to start what year is it?if its 2005 or newer have you ever changed the cabin air filter?most smells caused by the a/c are related to the filter.if not you have a bunch of leaves and trash built up at the fresh air vent in front of the passenger windsheild under the wipers.more than likely just a cabin filter.most are located just behind the glove box.

Switch to recycled air and spray Lysol or Oust into foot well, usually where recycled air is picked up. The Lysol will kill the stuff that is causing the bad odor. Do this when smell comes back.

Also pick up a desiccant bottle at Walmart. A desiccant bottle sucks up moisture.

fishy? sounds like a heating core problem. But I know nothing about cars so dont listen to me.