rear defrost problem help!!
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From: bc canada
rear defrost problem help!! every time i turn on the rear defrost it doesnt shut itself off and if idont shut it off myself it eventually dies along with the power seat. ive checked the fuse and it getas really hot before they shut down .ive replaced it but it doesnt help any other suggestions to what might be the cause??
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Joined: Oct 2002
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From: Edgewood, MD
Sounds like it's time to start checking the wiring. Have you installed anything electrical lately? Mine's not working right now and I haven't gotten around to checking the wiring yet. I know my problem started after installing some other guages so I'm starting in that area first.
Thread Starter
On The Tree
Joined: Jan 2006
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From: bc canada
no actually i havent install anything , at first i thought maybe one of the filaments on the back window had been cut but i cant find any breaks. the wiring on that could be fun to trace too.
The rear defroster is a common problem with F-bodies. I have a friend with an '01 formula and I have a '00 TA. Both of our cars will active the rear defrost, click it off early then the defrost will not work unless we let it cool for 5+mins at which point it only runs for maybe 20 sec at a time. He took his in to a dealer. They replaced the breaker, did a TSB recommended procedure that involves swapping out terminals in the fuse box, replaced the heater head unit, replaced some kind of timing unit, and now they're actually replacing the rear window. (essentially they're replacing everything.)
Alternatively he told me he found something online about people swapping the breaker out with a fuse and it fixing the problem.
Sounds like your problem could be this "timing unit"
Alternatively he told me he found something online about people swapping the breaker out with a fuse and it fixing the problem.
Sounds like your problem could be this "timing unit"
while we're on the subject of this...one of the filaments i think it is...the lines that come across the window is burnt out or something and doesn't defrost in that certain spot...is there any way to fix this particular problem? just curious...thanks guys
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Joined: Oct 2002
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From: Edgewood, MD
Originally Posted by Mike44138
The rear defroster is a common problem with F-bodies. I have a friend with an '01 formula and I have a '00 TA. Both of our cars will active the rear defrost, click it off early then the defrost will not work unless we let it cool for 5+mins at which point it only runs for maybe 20 sec at a time. He took his in to a dealer. They replaced the breaker, did a TSB recommended procedure that involves swapping out terminals in the fuse box, replaced the heater head unit, replaced some kind of timing unit, and now they're actually replacing the rear window. (essentially they're replacing everything.)
Alternatively he told me he found something online about people swapping the breaker out with a fuse and it fixing the problem.
Sounds like your problem could be this "timing unit"
Alternatively he told me he found something online about people swapping the breaker out with a fuse and it fixing the problem.
Sounds like your problem could be this "timing unit"
One thing to test that might help narrow down the problem somewhat..can you adjust your power seat while the defrost is on or during that period where it doesn't want to turn on? The power seat and the rear defrost is on the same circuit. From the reading I've done, if the seat still works, the problem is someplace starting with the wiring under the seat and running to the back glass...somewhere in that area. If the seat doesn't work, the problem is someplace between the seat forward (bad fuse, problem with a wire towards the front of the car..) I haven't heard anything mentioned before about a timing unit...so no clue if there's a timing unit or if it's bad on how it would affect the seat...
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Verdad Gallardo Ok, I went to work this morning, ran the defrost...sure enough, it (and the seat) quit a minute later. Stopped at the gas station and popped open the fusebox cover. When I tried to yank out the defrost/power seat circuit breaker it burned the f#ck out of my fingers!!! I mean, this thing was nearly as hot as a soldering iron! After letting it cool enough to pull it, I popped in a 30 amp fuse. Problem solved, works like a champ. Thanks a bunch guys! You rock!
Unless you like your fingers well done, don't touch the breaker right after it fails!
Unless you like your fingers well done, don't touch the breaker right after it fails!
Last edited by thunderdan74; Feb 2, 2006 at 06:10 PM.
Originally Posted by Sebring 00
Hope the circuit breaker that you replaced with the 30 amp fuse was rated 30 amp as well. If not, you might be melting wiring.
I had the same problem. the defrost and seat would quit after about 90 seconds, when it cooled off they would work again. replaced the breaker with fuse with the same rating. works perfect now and its been years since I did it.
It is in the fuse box on the side of the dash. Second or third one down on the left side labeled seat/defrost. Turn on your defrost and let it overheat and touch a few of them silver boxes in there. You'll find it soon enough!
