Condensation inside front and rear windows

[leaking123]

I have a 2017 mustang non convertible and there is always condensation inside the car on the rear and front windows when the temperature drops below 60 degrees outside. It’s only there at night when there’s no sunlight out. The inside is dry, floor is dry and I have a bottle of damp rid inside the try and absorb any excess moisture inside the car. I attached a photo for reference.
Few things to note, I do vape inside the car but I wipe down the windows with windex once a month. I always drive it with the A/C to dry the air inside the car. What are things I need to look for?

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[Skye]

Welcome to the Forums,

https://www.mustang6g.com/forums/threads/introduce-yourself.6728/

That there's condensation consistently entering the car shows an air gap or opening of some kind.

First, establish some kind of baseline:

- Stop vaping in the car
- Use the A/C, heat, fans and vents as-needed
- Get rid of the Damp-rid; it's potentially masking the root cause
- Get rid of the Windex. Stoner's Invisible Glass is readily available and works better
- Do a good, general cleaning of the car inside an out. You might notice something

Once that is done, open the hood, doors and trunk

- Inspect the rubber seals and how the panels close and fit
- See how the windows close, how well the glass seals against the gasket
- Look at the front and rear windows all-around, to see if there are any small openings, gaps, changes in the seam. There have instances of body seams cracking near the window corners

If you have access to water and a hose, sometimes using one in an area of interest can highlight a problem. Low pressure spraying, rain-like or mist. You're not trying to blast the surface.

Finally, you can review the following threads. There are some specific areas that can be quickly checked.

https://www.mustang6g.com/forums/threads/water-leaks-master-thread.123828/

https://www.google.com/search?q=mus...HTXeL1AQrQIoBHoECBwQBQ&biw=1466&bih=743&dpr=2

Try all that and see what comes about. Let us know what happened.

Not trying to get all Karen, but as a former smoker, consider quitting. As we get older, all our bodies accumulate various amounts of errors. Smoking and vaping only exacerbates those. I've been very fortunate, but I know from the time I did smoke, the odds of me developing certain diseases and cancers will always be higher than someone who hasn't. I'd like to avoid those as much as possible. Additional benefits of quitting include more money for mods and detailing supplies , better sleeping, more energy and the ability to smell and taste again.

Good Luck.

 

[Torched10]

Great post

 

[TonyT930]

Great post

Great post

 

[Johnnybee]

You may want to check the rear carpet for dampness. My understanding is that the coupes had water intrusion issues in the rear windows. Perhaps you have enough coming in to feed the condensation but not enough to be obvious.

 

[ORRadtech]

You may want to check the rear carpet for dampness. My understanding is that the coupes had water intrusion issues in the rear windows. Perhaps you have enough coming in to feed the condensation but not enough to be obvious.

Agree. I was going to suggest pulling the back seat base out and checking under there. I'm pretty sure that water could accumulate under there without ever having the carpet feel damp.

 

[Johnnybee]

Agree. I was going to suggest pulling the back seat base out and checking under there. I'm pretty sure that water could accumulate under there without ever having the carpet feel damp.

Actually you made me think of something else. I pulled my seat bottom at one point and both of the big rubber body plugs underneath were not fully seated, creating an opening to the bottom of the car.

 

[leaking123]

I know it’s been a year but I wanted to provide an update in case someone is having similar issues.
After reading through more forums and threads @Skye provided the Google link that helped a lot, I found the A pillar (TSB 22-2242: 2015-2022 S550's A-pillar water intrusion/leaks) to be the most useful. I replaced the “tape” with rubber seals PN: -W718717-S300 on both the A pillar. I thought that resolved my issue because I had 0 condensation inside the cabin from March 2025 until December 2025.
Starting December 2025, I noticed moisture inside the rear window only and decided to diagnose the issue again. I felt like there has to be something in the trunk that is allowing moisture to get in since there is no water inside at all.
I took apart the panels inside the trunk and found a similar tape covering a hole on the floor of the trunk.
Hopefully after replacing the “tape” with rubber plugs, the issue is resolved. Since I’m already in there, I replaced the trunk seal.

Apologies for the bad formatting, typing this on mobile. Feel free to let me know if there are any other body plugs that Ford covered up with “tape”.

 

[G.T.]

Thanks for coming back with the resolution! Will no doubt help others in the future.

 

[Skye]

Nice. . Glad you were able to work through those things.

Thanks for returning and providing us with an update. It will help others.

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