Mildew smell from A/C

[DreamBrother1]

I've had recurring mildew smell from the A/C the past couple years. I've tried some things. Lysol in the air intake. Frigi-Fresh in the air intake. Ozium in the intake. Kool-It kit foam sprayed into the drain to the evaporator a few times. New cabin air filters. I run the fan without A/C or recirculation for 5 minites at 75 degrees anytime I use the A/C to help dry out the system. These interventions help, but nothing lasts. Anyone with similar issues that tried anything else?

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[RickLightning]

Have you tried an activated carbon air filter?

 

[RocketGhost]

I get a mildew smell in my truck after it rains, I believe it is rainwater collecting in the sunroof drains, in particular the fabric wind deflector. In my case it's not the A/C. If I park in the rain I will smell mildew when I get in the truck before I even turn it on.

 

[tubby]

Do you see water dripping from the drain on a humid day with the A/C is running? If not, you may have a plugged drain tube...? Maybe you tested that out with the Kool-it kit foam.

 

[DreamBrother1]

Do you see water dripping from the drain on a humid day with the A/C is running? If not, you may have a plugged drain tube...? Maybe you tested that out with the Kool-it kit foam.

Thanks that's a good idea, I need to check on this again. I should also note for others, I have a Pro trim (no sunroof)

 

[ktom]

I get a mildew smell in my truck after it rains, I believe it is rainwater collecting in the sunroof drains, in particular the fabric wind deflector. In my case it's not the A/C. If I park in the rain I will smell mildew when I get in the truck before I even turn it on.

This is the same for me. The ford people have replaced all the A/C components and cleaned the drains in the past to my complaints. The smell still occurs, after it rains.

 

[Tom M]

I live in a humid climate and had a similar problem. The condensation from the air conditioning drips across a foam seal that is on the passenger side firewall. Try this: https://static.nhtsa.gov/odi/tsbs/2019/MC-10168762-0001.pdf

 

[BluesClues]

When replacing your filter, take Lysol spray and turn your AC on and blast it in for 30s.

I use the Bosch HEPA. Fixed this problem.

 

[CrimsonGhost603]

I see you’ve mentioned spraying Kool-It. Have you created a service port behind your glovebox? This helped me significantly with controlling the smell.

Steps I used

Spray cleaner

• Spray short bursts.
• Try a few angles to coat more of the coil.
• Let it sit
• Wait 10–15 minutes.
• Cabin filter still out.

First dry/run cycle

• Start truck.
• AC ON
• Fan HIGH
• Fresh air / recirc OFF
• Run 10–15 minutes.

Final dry cycle

• AC OFF
• Fan HIGH
• Fresh air still preferred.
• Run 5–10 minutes.

Check drainage

• Look under passenger/front area for water dripping.
• Dripping is good; it means the drain is working.

Reinstall cabin filter


SERVICE PORT:

 

[CrimsonGhost603]

As a side note: Simple Green AC coil cleaner is a much better product in my opinion, but the can needs an adapter. I finagled an aftermarket cap and drilled the end so it could use the wide spray nozzle from the Kool-It can. This only worked one time then it broke. The Lubergard Kool It can has a larger stem than the Simple Green coil cleaner can. If anyone can find a solution to this it would be great, as smaller nozzles do not work since the foaming action is required.

 

[hoovertac]

I've had recurring mildew smell from the A/C the past couple years. I've tried some things. Lysol in the air intake. Frigi-Fresh in the air intake. Ozium in the intake. Kool-It kit foam sprayed into the drain to the evaporator a few times. New cabin air filters. I run the fan without A/C or recirculation for 5 minites at 75 degrees anytime I use the A/C to help dry out the system. These interventions help, but nothing lasts. Anyone with similar issues that tried anything else?

Thanks for this post. I’ve recently started to notice a funky smell & keep the truck clean. Never made the connection that it could be the A/C. You seem to be doing more than I would recommend. If the smell has penetrated the carpet and upholstery an ionizer-machine session may be in order.

 

[RLXXI]

It did this on my last truck 2013 XLT, and it does it on this new one. I shoot Lysol under the dash where the fan intake is for recirc and up by the windshield where the fresh air intake is, fan on high, select your intake and blast half a can in there.

The smell eventually comes back so I chalk it up to just another maintenance item. I haven't tried the charcoal or hepa filter(s) yet so that's on the list, only have 3k on it.

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