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Rear Defog Not Working Well....

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Old Dec 26, 2003 | 11:13 AM
  #1  
joecool72's Avatar
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From: NW Burbs Chicago, IL USA
Rear Defog Not Working Well....

Hi all, before I run out to buy a new Rear Defog switch, I want to make sure this is the issue...

On my '96 Z, when I turn it on, it always shuts off way before the rear window is defogged. Once I try to turn it back on, it doesn't turn on immediately. I normally have to wait a few minutes, then it turns on again, but it always shuts off early again.

I've checked the connections on the glass and I've checked the fuse and everything is good.

Is it the switch or is there something else I'm missing?

Thanks!
Old Dec 26, 2003 | 12:06 PM
  #2  
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From: Shreveport,La USA
Wink

I dont remember all the particulars, But on mine,the power seat and the defogger is on the same circuit, i would adjust my seat, defogger go out--its a relay i think on the driver side fuse box that is bad--"seems" like i read you can replace the relay with a fuse and it will help correct that little problem--just to be safe you might want to do a search on it--Dwayne
Old Dec 26, 2003 | 01:17 PM
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Yes replace the circuit breaker with a 30 amp fuse...
see this thread from my post down:
http://web.camaross.com/forums/showt...hreadid=203276
Old Dec 26, 2003 | 01:22 PM
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I had the same problem and replaced it with a fuse and it stays on for almost 10 min like it's suppoes to.
Old Dec 26, 2003 | 06:00 PM
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Originally posted by Mtrhds94Z
Yes replace the circuit breaker with a 30 amp fuse...
see this thread from my post down:
http://web.camaross.com/forums/showt...hreadid=203276
Hey thanks guys, you made my day!

Replaced it with an extra fuse I had in my tool box and she works long now!

Any reason why it's just a matter of changing the 30A Circuit Breaker to a 30A Fuse??? Just curious....
Old Dec 26, 2003 | 06:36 PM
  #6  
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Originally posted by joecool72
Hey thanks guys, you made my day!

Replaced it with an extra fuse I had in my tool box and she works long now!

Any reason why it's just a matter of changing the 30A Circuit Breaker to a 30A Fuse??? Just curious....
My theory is that the CB gets 'tired/lazy' as it ages.. and trips at less than 30 amps.. and the fuse carrys the rated 30 amps better....
Old Dec 26, 2003 | 06:41 PM
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I had the same problem, fuse works better for me too.
Old Dec 26, 2003 | 09:43 PM
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The 30 Amp breaker develops a layer of corrosion/crust on the contacts, which increases its resistance, which makes it overheat at a much lower current draw. You can pop open the breaker's cover and clean the contact with a piece of fine sandpaper. The nice thing about a breaker is it will reset itself, where a fuse needs to be replaced.

BTW, I put a fuse in mine.
Old Sep 11, 2006 | 08:07 AM
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Re: Rear Defog Not Working Well....

Oh how I love the search feature. Seems like alot of people have had this problem. Gonna go put a fuse in mine now

Thanks a ton guys! This forum rocks.
Old Sep 11, 2006 | 08:18 AM
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Re: Rear Defog Not Working Well....

Originally Posted by PGR
The 30 Amp breaker develops a layer of corrosion/crust on the contacts, which increases its resistance, which makes it overheat at a much lower current draw. You can pop open the breaker's cover and clean the contact with a piece of fine sandpaper. The nice thing about a breaker is it will reset itself, where a fuse needs to be replaced.

BTW, I put a fuse in mine.
Long ago, the first thing I tried was a brand new breaker. No joy. I've been using a 30A fuse for 6+ years.
Old Sep 11, 2006 | 07:02 PM
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Re: Rear Defog Not Working Well....

I replaced my circuit breaker with a 30 amp fuse due to the fact it kept switching off too soon.

It was fine until I pulled off the fuse panel and found that the 30A fuse had melted, both the metal and plastic of the fuse. I had to pull the fuse teeth out with pliers.

I guess I have a short somewhere or something, you should check you don't have the same problem. I guess my breaker may have been doing its job in the first place.
Old Sep 11, 2006 | 07:08 PM
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Re: Rear Defog Not Working Well....

Originally Posted by CamaroUK
I replaced my circuit breaker with a 30 amp fuse due to the fact it kept switching off too soon.

It was fine until I pulled off the fuse panel and found that the 30A fuse had melted, both the metal and plastic of the fuse. I had to pull the fuse teeth out with pliers.

I guess I have a short somewhere or something, you should check you don't have the same problem. I guess my breaker may have been doing its job in the first place.
The defogger pulls a lot of juice. The fuse may get deformed, but should blow if too much current is pulled. Keep a spare fuse or two handy and check it every once in a while.
Old Sep 11, 2006 | 07:14 PM
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Re: Rear Defog Not Working Well....

I was suspicious as to why it did'nt just blow. I assumed it may have been a faulty fuse or something that took more current than it should have.

I have not actually tried another 30A fuse since, I just put the old breaker back in. Maybe I should try a new fuse and see if the same happens again.
Old Sep 12, 2006 | 08:05 AM
  #14  
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Re: Rear Defog Not Working Well....

I had the same thing happen with the fuse. The plastic just ran right off the metal. I got a bit worried, and saw someone say about taking some sandpaper to the terminals of the breaker. Did that and the thing stays on for the full 10 minutes I do still have a few 30 amp fuses in the glove box though, because i'm sure it will come back sooner or later.
Old Apr 21, 2011 | 09:30 PM
  #15  
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Re: Rear Defog Not Working Well....

FYI I did this mod about 4 years ago... I opened up that fuse panel yesterday to find my 30 amp fuse melted and dripped onto the breaker below it. I am surprised it didn't start a fire or something! Very scary! Now I want to fix it right... how does one go about doing that? I wish I knew what I did with that old breaker... ugh!



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