HUGE problem... Rear defroster blew rear window out !!!
 

Hello, any help would be great....My wife was driving my Monte (I had hers in the shop putting a remote starter for X mas) and she was driving with the temp about 10 deg. and she put the rear defroster on, (it cycled 3 times, shut off after a couple minutes each time.) then, the 4th or 5th time BLAMMO !!!!! REAR WINDOW BLEW UP !!!!!!!.. I had a new window installed and dont want it to happen again after $300 bucks , so, do I plug the defroster back in? or can the problem be a relay etc..... please help....I live in Wisconsin so its cold as hell here and need a rear defroster..thanks in advance....Michael....

holy sh!t, that is just crazy.....

Did you say you cycled the defrost 5 times?!?! You definately arent supposed to run the rear defrost for that long. Thats why it shuts off on its own.

I have no idea what would cause that. Maybe with it so cold and heating the window up it did that. I have never seen a window do that.

Its hard to tell for sure. If the window was real hot from having the defrost on for a while, and a chunk of slush or snow came off the roof down onto the glass, the sudden change of temp could have caused the glass to shatter. The defroster should only be used to initially clear the window. It shouldnt be kept on for more than one or two cycles. If it doesnt melt it the first time, use a scraper to clear off what is left.

not me....
 

This was done by my wife, not me, I was @ home....lol She said she cycled it 3-4 times because it kept getting frosty ( the winter in Wisconsin is brutle cold) but Im not positive how many times she did.I know the relay does shut it off after it cycles and ive ran one thru 3 cycles before with no issues at all....Ive never heard( as said above, till now a window BLOWING UP because of the defroster.).. MJ

Very strange. I just read my owner's manual and there are no dire warnings in regard to repeatedly pushing the defrost button. It just says that the defroster will stay on for 10 minutes the first time and 5 minutes if you press it again.

I think the heat from the front window defroster is hotter than the back defroster would ever get. I've had cars that blew out ridiculously hot air from the front defroster and the window never blew out.

I read on one web site that the rear defrost elements only heat to about 85 degrees. If you run your defroster and place your hand on it, it should barely feel warm. If it gets "hot", then you have an issue.

Hopefully what happened to you was a once in a lifetime event.

Tell her to Turn Down the BASS! lol

I've never heard of that happening before.

Craziness
 

I have never heard of that happening in any car..ever. To be honest, it was probably a freak sorta thing. First of all its friggen freezing in Wisconsin so the glass was as cold as it could be, and if you were defrosting the hell out of it, the glass could have been weak. Most likely wont happen again..ever.