Front Windshield defog problem
Thread Starter
Burning Brakes
Joined: Apr 2009
Posts: 828
Likes: 2
Front Windshield defog problem
In my 77 I have a solid, heavy air stream on my inner front screen when I need to de fog it. It seems that it just gets worse when I turn on defrost at any fan speed or any heat setting.
I have to carry a towel with me to wipe the screen while driving in rain, etc.
Has anyone had this and was able to correct it?
Thanks
Jack
1977 L-82
I have to carry a towel with me to wipe the screen while driving in rain, etc.
Has anyone had this and was able to correct it?
Thanks
Jack
1977 L-82
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,753
From: Charlotte NC
Jack,
You lost me. I read your post several times and I can not figure out what you are saying your problem is.
Is it that you ALWAYS have air going to the defroster...regardless of the position of your A/C control....OR....
Is it that the windshield is fogging up...regardless if the defrost is on or not.
Do you ave the ability to change the air and make it come out of the center vents??? IF you always have air coming out on the floor...then either you lost vacuum to you control head...or the vacuum switch on your control head is bad and leaking enough so that the system will go into default mode and always put the air out on the floor and some at the defroster.
DUB
You lost me. I read your post several times and I can not figure out what you are saying your problem is.
Is it that you ALWAYS have air going to the defroster...regardless of the position of your A/C control....OR....
Is it that the windshield is fogging up...regardless if the defrost is on or not.
Do you ave the ability to change the air and make it come out of the center vents??? IF you always have air coming out on the floor...then either you lost vacuum to you control head...or the vacuum switch on your control head is bad and leaking enough so that the system will go into default mode and always put the air out on the floor and some at the defroster.
DUB
Thread Starter
Burning Brakes
Joined: Apr 2009
Posts: 828
Likes: 2
Jack,
You lost me. I read your post several times and I can not figure out what you are saying your problem is.
Is it that you ALWAYS have air going to the defroster...regardless of the position of your A/C control....OR....
Is it that the windshield is fogging up...regardless if the defrost is on or not.
Do you ave the ability to change the air and make it come out of the center vents??? IF you always have air coming out on the floor...then either you lost vacuum to you control head...or the vacuum switch on your control head is bad and leaking enough so that the system will go into default mode and always put the air out on the floor and some at the defroster.
DUB
You lost me. I read your post several times and I can not figure out what you are saying your problem is.
Is it that you ALWAYS have air going to the defroster...regardless of the position of your A/C control....OR....
Is it that the windshield is fogging up...regardless if the defrost is on or not.
Do you ave the ability to change the air and make it come out of the center vents??? IF you always have air coming out on the floor...then either you lost vacuum to you control head...or the vacuum switch on your control head is bad and leaking enough so that the system will go into default mode and always put the air out on the floor and some at the defroster.
DUB
Long time, I hope all is well. My console switch is fine. If I start getting a fogged up front windshield, no matter what position the bottom lever is in (hot or cold) and I have only the defrost air on, at any fan speed, nothing clears the inside fog except a small towel on the seat next to me. All positions on my switch work fine.
Thanks
Jack
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,114
From: Crossville TN
There is probably a small leak that has started in the heater core. Any fluid leakage there will provide ADDITIONAL water vapor that condenses on the window when you use the Defrost function.
Safety Car
Joined: Nov 2008
Posts: 3,713
Likes: 550
From: Seattle Washington
Or there are some Wet Leaves or Rags or what ever a mouse had draged in to the system wich could be just about anywhere. I'd start by looking under the Cowl of the Hood. I think most if not all modern cars have the AC on when in defrost mode. It drys the air. If your Vette dose't have AC it might not work like you think it should.
Le Mans Master
Joined: Sep 2002
Posts: 5,235
Likes: 898
From: Myrtle Beach SC
You might want to get to that heater core before it leaks or dumps coolant on your carpet
Thread Starter
Burning Brakes
Joined: Apr 2009
Posts: 828
Likes: 2
Or there are some Wet Leaves or Rags or what ever a mouse had draged in to the system wich could be just about anywhere. I'd start by looking under the Cowl of the Hood. I think most if not all modern cars have the AC on when in defrost mode. It drys the air. If your Vette dose't have AC it might not work like you think it should.
Heater core is on it's way.
Thanks
Jack
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