Hey everyone.

I tried a search and only found one thread pertaining to this issue. Has anyone else had the problem where the front windshield fogs up a lot? I notice it particularly after using the a/c and then not using it. When the windows are closed especially or when it's raining, the windshield fogs up like crazy. I'm suspecting a plugged evaporator drain...here's why:

Over the winter I noticed that the blower motor would "seize", only when it was really cold out - such that it would freeze water. So, if the evaporator is plugged, the water it pulls from the air can't escape, thus collecting in the airbox and freezing the fan, until the car is warmed up and enough air passes through from normal airflow and heat characteristics, then the fan works again.

The other day I ran the a/c for about 25 minutes during my lunch break and looked under the car. Usually you'll see a little puddle of water. However, it was bone dry. Again, leads me to believe the drain is plugged.

I put the car up on the lift at work today and grabbed a blowgun with an extended tip and tried blowing air through the drain under the car. It seems as if the air wasn't able to enter or move at all into the drain tube. Being that I don't want to put a hole in the evaporator I didn't push too hard into it. But, after 10 minutes of trying to blow air through, I gave up and nothing drained.

I don't hear any water sloshing around in the dashboard at all, so I don't believe a lot of water is collecting, but enough to steam up the windshield and freeze the fan.

Has anyone else had this problem? I'm really leaning towards it being something with the evaporator. I've checked my coolant and haven't lost any in the last year or so since I did my coolant flush, so I don't believe it's a heater core leaking (plus it doesn't smell like coolant inside the car). Sorry this is so lengthy!

Any help would be greatly appreciated! Thanks in advance!

-Sean

 

My front windshield fogs up a good amount now since cold weather is here. People say it's because of smoking in the car. Not sure if you do or not.

 

No sir, car is NOT smoked in. Hasn't been by me, or the previous owner (as far as I know, haha).

 

it's just simple condensation, perfectly normal. A/C dries the air hence no more fogging also make sure your not on recirculate that will fog them up too

 

open your window a crack.

 

my front window fogged alot just before the heater core blew. Check the hose's running into it and out of it for cracking. Have you been getting as hot of air?

 

Thanks everyone so far. No hot air coming from the vents just being open (EATC off, recirc not enabled). It'll blow hot air if I have the EATC set to 90 or anything higher than ambient temp though, which is expected. It doesn't seem like it's just condensation since it's only the windshield and the streaks that appear on the windshield don't seem like just condensation. I'm really convinced there's an issue with the evaporator and drain but haven't had a real chance to tear into it. Anyone else have any ideas?

 

Try washing the interior of the windshield a bit with water only , no soap. Grease on glass absorbs moisture, and creates fog.

 

Try rainex anti fog on the windsheild or wash the inside of the windsheild with vineger.It really works.

 

I would work on being absolutely sure the drain is working. You said nothing comes out when it should, and you gan't get arflow through.

Obviously cleaning the windshield is not going to unfreeze a fan.
You could also start some mold and mildew, and have a stinker, that has happened to friend's and other cars I've known.

A pinhole heater core leak will steam up the windshield too, but you would be smelling coolant too.

 

heater core leaking? ck it out

 

I'm pretty sure it's not a heater core leaking. If it were, I don't think it would cause the fan to freeze in cold ambient temperatures (think coolant/antifreeze). Hopefully by the end of the week I'll have enough time to jump into this further. I'm almost certain it's due to the drain not emptying properly. I had a car in the shop one time and the complaint was that the windshield fogged up and steam came from defroster vents. That ended up being a clogged evaporator drain. Again, I'm not worried about the fact that the windshield is just fogging up. I'm concerned about WHY it's fogging up. I haven't touched the a/c in a few days and haven't had a problem since. Also, I forgot to mention that the windshield does not fog up at all if the EATC is in RECIRC mode (when the unit is off), hence blocking outside airflow into the cabin and not moving any air. I'm really hoping it's as simple as the drain being blocked somehow and I can clear it. If anyone else has suggestions please feel free to throw them out there. Thanks again everyone!

 

In the rain with recirculate on I think everyones windshield will fog.I know my last 2 maxima's did with no heater core or any other problem.

 

Yeah...well hopefully I'll find out tomorrow more about what's going on inside. I'm takin my car into the shop tomorrow and I'm gonna tear apart the fan/blower unit. Might stop at the dealer and get a new cabin filter while I'm in there. I'm hoping it's as easy as a blocked drain from the inside, but who knows. Tomorrow I'm hoping to know for sure.

 

fog on the inside is usually caused by a lack of fresh air from the outside. when i run recirculation mode too long during the winter, my windows fog up. the moment i go back to fresh air, they go away.

 

Vinegar or rubbing alcohol. But the Rain-X anti-fog wipes suck, IMO. I used them and they left a weird residue on my windows that made them fog up even worse.

 

Excellent news! I think I found the problem. No, I'm not simply trying to prevent the windshield from fogging by preventing it from sticking on the glass...I'm trying to prevent the fog! Today I took my car into work and yanked the glovebox out to get to the HVAC box. First thing I did was yank out the in cabin microfilter (pollen filter) and HOLY HELL! It was the nastiest thing I've ever seen. And I mean ever. There was a whole ton of crap built up inside that had to be sucked out even after I pulled the filter out. I ran the A/C for a little bit with the air filter removed and voila! I finally have water draining from my car! I know, sounds sad, but it's the little things that really keep me going. The filter was so clogged and with all the excess buildup, the water had nowhere to drain to! I got a replacement filter (there was no way I was even gonna try washing this) from the dealer for $45 ($50+tax list, I get a 10% dealer discount). The new filter is a two piece design and not washable (like the original). After putting in the new filter, I gotta say the air just smells so much cleaner! I never really knew how nasty the air I was breathing in was until now. Makes me upset that I didn't think of it sooner, I could've really enjoyed the a/c this summer. As for now I think the problem is solved, but it will take a few days and nights of driving with the a/c on and off to really see if the windshield fogs. But at least now the evaporator is draining normally, and it's a step in the right direction. As happy as I am, it's a little upsetting because it's considered NORMAL maintenance, and something I should've done previously. But I'll update again in a few days, hopefully with the news that the fog is gone! Thanks to everyone for their input!
By the way, check this out for pictures of just how nasty this thing was!
http://www.cardomain.com/ride/3245762/3

-Sean

 

Wow, dude...do you go tearing through fields for a living?

Good info, thanks for sharing, though.

 

Wow dude! lol that's the OEM filter. That's been in there since the factory! A Whole 7-8 years!

 

Should have seen my incabin air filter. The dam thing was completely black, warped and flat like a pancake.

It was the original too, 7 years old. Got a replacement from the scrapyard(i went there for another reason) the other day for free, only a couple of months old.

 

lol I WISH that was my excuse. I never though of it being an issue and apparently neither did it's original owner haha.

Yeah, it's pretty sad. And from what I've read this filter's washable? I'm sorry, something that gross I don't wanna be breathing in just knowing what I saw!

For those who were wondering/interested, the P/N listed is:

999M1-VP004

So, as far as updates go...it's been two days since the install of the new filter. I haven't seen a spot of fog yet! Which makes sense, because the water can actually DRAIN from the vehicle rather than build up in it.

Hope this helps someone down the line!