Windows fog up uncontrollably.

[Jarrett]

I've read many threads on this site and the general internet about how the issue I'm about to describe is simply part of owning an old car. The only thing that I can do in order to differentiate my circumstances from the general complaints is to ask that you not think I'm being dramatic when I describe how intense the conditions are in my car. So, here goes...

My car had a failing blower motor going into the winter season. I know this because I could hear it whine even though it seemed to do its job. Eventually, that stopped and it would do nothing at all. I still technically had climate control in the car, but with no force to push air across a heater core or evaporator, I effectively didn't. This winter has been a particularly wet one. On cold mornings I have woken up to find that the windows and windshield are fogged with unbelievable amounts of condensation. No manner of wiping them with a cotton t-shirt or anything can make the windows clear up. Using the wipers only controls the outside of the glass (obviously) and not much of the problem is on that side. I assumed that most of this was caused from not having a blower motor that functioned properly to allow the A/C to rid the cabin of condensation.

Well, this past week I took the blower motor from my other 1993 coupe and replaced my bad unit. The motor was now working so I assumed my problems would go away. Not really much difference at all. To quell any questions as to whether I am using the A/C with my defroster, yes, I am. I have tried both fresh and recirculating air to no avail. The only times I really drive my car is on Saturday afternoons to drive from Houston to College Station and then early AM on Monday to come back to Houston for work. My problems are strictly in the early morning portions of my commute. It's been raining frequently, and humidity is just an ongoing problem here, and the cold keeps moisture condensed. While this is nature, and I'm not trying to combat the physics behind the phenomena of condensation, I am a bit perturbed that this car is the only car of mine to exhibit these issues. No other Accord of mine has been this bad.

So, what are my options? I'm thinking about putting silica-based kitty litter in some tube socks and hiding a few in the car to rid the insides of moisture. I saw this on a Youtube video and it seems like solid logic. How much it can overcome remains to be seen. I need a new windshield anyway, so I'm going to pay extra close attention to the installers making a completely perfect seal when the new one goes in. I doubt that any problems extend from here, but who knows. I also bought a set of JDM coupe visors I still need to install. I didn't want to until all of the body work was done, but this is a safety issue and that's good enough of a reason for me. All of the door seals seem to be in good shape with no obvious dryness, cracking or voids. Any other thoughts? Again, the defroster simply isn't doing anything. I'm using A/C while running the heater and regulating between multiple temperatures. These trips are two hours long so I guarantee that with the variances I've tested, I have enough sample time with each that I would have noticed an improvement had one been present. I'm wiling to listen to silly ideas at this point. I'm nearly prepared to take it to the dealer to let them look at it.

Thanks for reading.

[cp[mike]]

This was happening to my old '93 sedan. I feel it is due to the body of the car being open to the atmosphere, and/or specific water leaks. I also wonder if any of your Vapor Barrier sheets are missing/open from behind your door panels?

Definitely take care of the windshield while youre at it, but the same issue may apply to the rear window. Or rust holes in the trunk. Or a loose antenna. Or the side mirror mounts. Or dry taillight gaskets. Or door seals. Anything, at this point. You may not be aware of the leak, or its to an area that you don't see, but it is probably letting moisture into the car. Any evaporation overnight makes the humidity rise, and condense on the cold windows (or mine used to fog up the gauge cluster and mirrors, too). It is probably also condensing on the back of the rear upper seat, under the carpet (check there in the morning!)

The car is designed to be pretty airtight, and there is a flap under the rear left edge of the bumper that is designed to typically stay closed, but opens to let the air pressure/vacuum to normalize from the doors being opened/closed. This is supposed to keep the dry, air-conditioned air within the car, so it is sitting overnight with dry air, and not open to the atmosphere at all while it sits. This normally keeps the humid morning dew out. I have a feeling the airtight seal is compromised for your car - water/humid atmospheric air is getting in, and the humid air isn't getting out.

I found the only solution was to exchange the air in the vehicle. I would open the back right window, then open the vents. Air would pass from the outside front of the car, thru the cabin, and back out. Quickest way to vent out the car, but doesn't work very well if its still very humid out. At that point, only AC would help.

P.s.: My old car had a history of water leaks, a couple body plugs removed, holes drilled in the trunk, etc. It would have the same problems as yours. It was hard to open the windows and let it vent, while its raining for weeks, and freezing cold. Heck at that point water used to actually run down the inside of the glass and collect in the rubber edge at the bottom. My A/C wasn't working either and it just got constantly worse. I wanted some window visors so i could still vent the cabin while it was raining, but never got around to it. You are probably also harboring some extra moisture that NEVER quite dries - like the matting under the carpet in the corners of footwells.

I ***HATE*** this issue you are describing. I'm pretty sure the moisture was causing other things to start going bad, like the shifter, and speaker cones and stuff. It LOOKED nice, but I ended up selling the car for cheap just to get rid of it.

[Losiracer2]

You could also try the RainX Anti-fog treatment on the insides of your glass to see if it helps.

[Fleetw00d]

The other possibility besides all the water leaks cp[mike] describes is that you have a leak in your heater core which is putting moisture into the car, especially when you're trying to dry it out!

The flap at the left rear is to allow the air coming in at the front of the car to escape. With all the windows closed, fresh air comes in at the front, flows through slots at the back of the rear shelf/base of the rear window into the trunk, then out through the flap. I almost always have my fan on low with fresh air selected so the air is always being exchanged, whether I'm using AC, vent, or heat.

Is this the one that came from Seattle? I'm not sure how easy it is to get to, but check the drain from the heater core/evaporator core box. If that is plugged, you could be pumping moist air into the car all the time as well.

[93redcb7]

i have this issue also, i found getting a ez air, it grabs the moisture out of the air and puts it in a little bowl thing in the bottom. I've heard of little can things you can get also or you can fill a sock full of cat litter and put it on your dash(havent tried this but heard it works)

[djcaz_aom]

I usually clean my windows to an extreme. I'll explain.

First clean windows with a microfiber sponge, using exterior car soap.

Next dry with clean microfiber cloth.

Next, I clay the window.

Then, I wax the window with my favorite synthetic wax.

Buff to a shine.

I also do the socks filled with Cat Litter method, one under each seat.

[Jarrett]

The other possibility besides all the water leaks cp[mike] describes is that you have a leak in your heater core which is putting moisture into the car, especially when you're trying to dry it out!

The flap at the left rear is to allow the air coming in at the front of the car to escape. With all the windows closed, fresh air comes in at the front, flows through slots at the back of the rear shelf/base of the rear window into the trunk, then out through the flap. I almost always have my fan on low with fresh air selected so the air is always being exchanged, whether I'm using AC, vent, or heat.

Is this the one that came from Seattle? I'm not sure how easy it is to get to, but check the drain from the heater core/evaporator core box. If that is plugged, you could be pumping moist air into the car all the time as well.

I told myself before writing this that I would be sure to include all relevant information so as to distinguish this from the general complaints of fogged windows. You've caused me to realize that I failed.

I have noticeable steam coming from the vents that I didn't really think anything about. I figured with the cold that it was just steam like you'd seem from your breath. There is also a distinct coolant smell in the cabin when it's running. Again, I've just assumed that this was natural because of the coolant running through the heater core. I know it's a closed system, but it wasn't odd enough to make me think it could be a leak. Now that you mention that, there was a very small amount of coolant beneath the carpet this weekend when I swapped it out for my black one. There was no moisture in the evaporator when the blower motor was removed. Just the usual pile of leaves that doesn't stop coming out. The drain is certainly going through the firewall, which I've seen some pointed straight down to the carpet inside for whatever reason, but I don't know if it's clogged.

I have the heater core from the same parts car that I can grab to swap them out. I have a '93 SE sedan dash swap I planned to do eventually so it looks like the time table on that just got moved up. There are a whole lot of things I can do at the same time if I'm pulling that thing out as well.

So is this the current hypothesis? My heater core has a leak in it somewhere?

[djcaz_aom]

Well, that changes things. I would go with the core leaking.

[F22Chris]

I had my heater core go on my Jetta. It fogged up the mirrors like crazy; even on hot days when the thermostat opened. You can usually smell the coolant, and the residue it leaves behind is a bit oily. So if you wipe it off and it just spreads, or smell coolant, then I'd look into the core. Mr.Clean Erasers are what I used to get the residue off. You can just use bleach if you want.

[Jarrett]

It would make sense that what's on my windshield is some type of oil from the coolant. It simply doesn't wipe off. Thanks a lot for the help, guys!

[Raf99]

I would of never thought of that for the resolution. When you do tackle the problem take some pictures as I'm sure others are probably having the same frustration as you.

[Fleetw00d]

I have noticeable steam coming from the vents that I didn't really think anything about. I figured with the cold that it was just steam like you'd seem from your breath. There is also a distinct coolant smell in the cabin when it's running. Again, I've just assumed that this was natural because of the coolant running through the heater core. I know it's a closed system, but it wasn't odd enough to make me think it could be a leak. Now that you mention that, there was a very small amount of coolant beneath the carpet this weekend when I swapped it out for my black one. There was no moisture in the evaporator when the blower motor was removed. Just the usual pile of leaves that doesn't stop coming out. The drain is certainly going through the firewall, which I've seen some pointed straight down to the carpet inside for whatever reason, but I don't know if it's clogged.

I have the heater core from the same parts car that I can grab to swap them out. I have a '93 SE sedan dash swap I planned to do eventually so it looks like the time table on that just got moved up. There are a whole lot of things I can do at the same time if I'm pulling that thing out as well.

So is this the current hypothesis? My heater core has a leak in it somewhere?

The only time you should see "steam" coming from the vents is a hot, humid day and you've got the AC cranked. It cools the hot air enough to cause the water vapor to condense (much as your warm breath does on a cold day). Remember, warm air can "hold" more moisture than cold air, so warming cold air should never result in condensation. If you're seeing steam at cold ambient temperatures it means you're adding moisture to the air, most likely by a leak as we've already discussed.

[Jarrett]

In my case, it would make sense that the appropriate action until the issues is corrected would be to not run the air conditioner at all.

Then again, if this is related to the heater core, then why does it still seem to present itself when the temperature is turned down low? I admit I don't run it cold because it's comfortable, but I've just tried to vary every single input on the HVAC unit to correct the issue. There have been times I've driven on these trips where the A/C has been blowing on full cold and I haven't noticed any change in the defroster. Isn't the heater eliminated from the equation at this point?

[wagon-r]

If it is the heater core, you should be able to minimize the problem by turning the temperature dial all the way down. This will shut off the valve that is between the engine and the firewall and should prevent coolant from flowing to the heater core.

You will likely get some residual leakage from coolant that is already in the heater core. The bigger problem is that the temperature dial often doesn't work well in older cars (I just replaced the one in my 1997 Accord). So, you might want to get under the hood and close the valve by hand, just to make sure it is fully closed.

If this doesn't make a difference, then chances are its not the heater core.

[h22sparkle]

I honestly think you should check the freon in the system. It may be too low if you already have the blower motor already up and running.