Windshield fogs up when it rains...anyone know the fix?
07-06-2003, 10:21 PM
#1
Burning Brakes
Thread Starter
Windshield fogs up when it rains...anyone know the fix?
I've only driven my car a few times in the rain (today being one of them) and now I remember why...the windshield fogs up so bad I can't see no matter how I adjust the ventalation system. Its a vert with AC and everything seems to work fine...except of course when it rains. My guess is that outside air is not entering into the car and I'm recirculating the cars interior air. I did check the valve behind the kick panel...it moves fine and while I can't see the plenum valve I can only assume it works. Does anyone know how to check the planum valve or have a solution to this problem.
[Modified by PaulH, 9:23 PM 7/6/2003]
[Modified by PaulH, 9:23 PM 7/6/2003]
07-06-2003, 10:38 PM
#2
Safety Car
Re: Windshield fogs up when it rains...anyone know the fix? (PaulH)
I guess your A/C isn't working, huh? The only way to cure it is to make the temp inside the car, especially around the glass as cool as the outside or colder and/or to remove the moisture from inside the car.
[Modified by LAvetteman, 9:40 PM 7/6/2003]
[Modified by LAvetteman, 9:40 PM 7/6/2003]
07-06-2003, 10:49 PM
#3
Team Owner
Re: Windshield fogs up when it rains...anyone know the fix? (LAvetteman)
Also try the Rain X "Anti-Fog", I find it helps a lot. It is applid to the interior side on the windshield to reduce the fog.
:cheers:
:cheers:
07-07-2003, 11:10 AM
#4
Instructor
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Re: Windshield fogs up when it rains...anyone know the fix? (Corey 68)
Well... the solution has become very clear to me, and I have recorded it in steps.
1. Install "Glad" protective measures, such as carpet & seat bags. Keep your car away from the garbage truck after this step is completed.
2. Adjust convertible top so it is now located in the down position
3. Put milk crate on passenger and drivers seats. Be safe with this step, and run a loop through the seatbelt to ensure the crate doesn't slide off or anything funky like that.
4. Enjoy new rainproof rag-top, while seeing right over your windshield. :troll
1. Install "Glad" protective measures, such as carpet & seat bags. Keep your car away from the garbage truck after this step is completed.
2. Adjust convertible top so it is now located in the down position
3. Put milk crate on passenger and drivers seats. Be safe with this step, and run a loop through the seatbelt to ensure the crate doesn't slide off or anything funky like that.
4. Enjoy new rainproof rag-top, while seeing right over your windshield. :troll
07-07-2003, 12:01 PM
#5
Drifting
Re: Windshield fogs up when it rains...anyone know the fix? (PaulH)
When I had this problem, it was because my heater core was leaking, and it was causing the interior to "fog up" with a filmy coating.
07-07-2003, 12:12 PM
#6
Instructor
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Re: Windshield fogs up when it rains...anyone know the fix? (rainman69)
Er yeah, I should've said that too... my car currently has the heater core bypassed because of this exact symptom. It leaks rad fluid and stuff.
07-07-2003, 02:02 PM
#7
Race Director
Re: Windshield fogs up when it rains...anyone know the fix? (rainman69)
When I had this problem, it was because my heater core was leaking, and it was causing the interior to "fog up" with a filmy coating.
When my core died the windows immediately fogged up. It was dark and I barely made it home. Kept wiping the window with a rag and it made a horrible mess as the "fog" was a greasy film.
Then I had the pleasure of replacing the heater core in a 454 AC car. I formulated a theory during that experience that boils down to the way they built corvettes in 2 easy steps:
1. Suspend heater core above assembly line.
2. Build car around heater core.
07-07-2003, 02:05 PM
#8
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Re: Windshield fogs up when it rains...anyone know the fix? (rainman69)
When I had this problem, it was because my heater core was leaking, and it was causing the interior to "fog up" with a filmy coating.
Another vote for heate core, I replaced mine and no problems since. Gotta have the defrost/fog on cool evenings in the country. :thumbs:
07-07-2003, 02:26 PM
#9
Burning Brakes
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Re: Windshield fogs up when it rains...anyone know the fix? (Fevre)
Heater core may be it. That happened to me on a different car years ago. However, since you bypassed it, the filmy stuff should not be getting into your ventilation system - but it probably is anyway! Make sure your a/c works and check for defrost air when you roll the slider that way. Our cars have many areas that can leak off the forced air before it gets to the windshield. Be sure you have 200mph-taped (a new verb!) over the joints behind the dash for the plastic air boxes. Also, check the fiberglass box around your a/c evap and the heater core under the hood on the firewall. When I bought my car, I had nothing but hot air blasting my feet. I had a two-inch piece of material missing - but looking through the hole the evap looked new! I fixed the hole with mat and resin - works like a champ now getting forced air through my vents, etc...
07-07-2003, 11:14 PM
#10
Melting Slicks
Re: Windshield fogs up when it rains...anyone know the fix? (Corey 68)
Also try the Rain X "Anti-Fog", I find it helps a lot. It is applid to the interior side on the windshield to reduce the fog. :cheers:
07-07-2003, 11:35 PM
#11
Burning Brakes
Thread Starter
Re: Windshield fogs up when it rains...anyone know the fix? (LAvetteman)
I guess your A/C isn't working, huh? The only way to cure it is to make the temp inside the car, especially around the glass as cool as the outside or colder and/or to remove the moisture from inside the car.
[Modified by LAvetteman, 9:40 PM 7/6/2003]
[Modified by LAvetteman, 9:40 PM 7/6/2003]
07-08-2003, 10:07 AM
#12
Team Owner
Re: Windshield fogs up when it rains...anyone know the fix? (PartTimeGenius)
Also try the Rain X "Anti-Fog", I find it helps a lot. It is applid to the interior side on the windshield to reduce the fog. :cheers:
Wow, I tried that stuff and had the opposite result. On anything other than the sunniest day, the inside of the windshield would be hazy from that garbage. It took me years and dozens of chemicals to get all that crap off. Sad thing was, it didn't help the real fogging problem a bit.
Wow, I tried that stuff and had the opposite result. On anything other than the sunniest day, the inside of the windshield would be hazy from that garbage. It took me years and dozens of chemicals to get all that crap off. Sad thing was, it didn't help the real fogging problem a bit.
I hate all the Rain X stuff. I put some on one of my cars a while back and regretted ever doing it. It gets dirty easily and is a real pain to get the crap off......don't do it. I vote for heater core also but since you have it in bypass mode (like me :D ) then you shouldn't have any anti-freeze getting into the vent system unless the core still has anti-freeze in it or you have a pool of it in your heater core area.
07-08-2003, 10:20 AM
#13
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Re: Windshield fogs up when it rains...anyone know the fix? (PaulH)
I guess your A/C isn't working, huh? The only way to cure it is to make the temp inside the car, especially around the glass as cool as the outside or colder and/or to remove the moisture from inside the car.
[Modified by LAvetteman, 9:40 PM 7/6/2003]
After replacing the heater core and evaporator, all seals and a full recharge I thought I had this system working, but LA vetteman is correct, it turns out my system is not holding a charge and its not blowing cold air on the windshield. But here is where I'm confused...not all vettes have air, and when the system is put in defog mode, fresh air should be enterring the vent system which should equal the outside air and prevent fogging. So even if my air is not working, putting the system in defog, should still clear the glass...so my thought is that the fresh air vent is not opening and I'm recylcing interior air causing the fogging. Has anyone found a way to test these? There is nothing in the GM service manual.
[Modified by LAvetteman, 9:40 PM 7/6/2003]
After replacing the heater core and evaporator, all seals and a full recharge I thought I had this system working, but LA vetteman is correct, it turns out my system is not holding a charge and its not blowing cold air on the windshield. But here is where I'm confused...not all vettes have air, and when the system is put in defog mode, fresh air should be enterring the vent system which should equal the outside air and prevent fogging. So even if my air is not working, putting the system in defog, should still clear the glass...so my thought is that the fresh air vent is not opening and I'm recylcing interior air causing the fogging. Has anyone found a way to test these? There is nothing in the GM service manual.
BTW I saw this trick on PBS where you spread shaving cream on a bathroom mirror and it will not fog up. Guy spread it on half a mirror and used a steam gun, the half with the shaving cream did not fog up. Supposed to last 3 to 4 weeks. Not sure what in the cream makes it work but it did.
[Modified by Fevre, 9:22 AM 7/8/2003]
