Rear windshield

[chompster4runner]

Rear window

So Christmas eve my wife was driving to work in the early morning. As she was getting ready to exit off the freeway she smell something burning and then POW! The rear window blew out. Because of the holiday most places are closed. I know a local yard has a few 4runner but was wondering if I should go for new and has anybody experience this?

Thanks!

 

[Buckles]

This is not too uncommon. Did she have the rear defroster on by chance?

 

[chompster4runner]

This is not too uncommon. Did she have the rear defroster on by chance?

She did had it on as usual. Temp here is around high 50's to low 60's in the morning. So far the price for new is around $200 without install. I plan to install it myself. Hopefully the defrost wires are OK and not fried.

 

[me_rikey]

This is not too uncommon. Did she have the rear defroster on by chance?

Uhh.. it's not uncommong for the rear window to shatter? This is new to me.. Does anyone know what causes this?

 

[bpowa]

that sucks.. After reading a few of these threads, I think about it every time I turn on the rear defroster.. Which is basically every morning this winter. I consider this a safety issue since I have a newborn in the back.. It would kill me if there was glass getting on him.

 

[me_rikey]

that sucks.. After reading a few of these threads, I think about it every time I turn on the rear defroster.. Which is basically every morning this winter. I consider this a safety issue since I have a newborn in the back.. It would kill me if there was glass getting on him.

The general consensus is to not use the rear defroster, to mitigate the issue? I don't think I can do that..

 

[chompster4runner]

Yea it sucks as this is our family hauler. Without a solution I guess we'll just avoid using the defroster for now. Googling this shows other Runner with the exact same problem.

 

[dleeallen]

$200 for new? Where? I see around 400+ for new. I need one for mine.

 

[me_rikey]

This is crazy. Has anyone brought this up to Toyota or the NHSA if applicable?

 

[JEL]

This is crazy. Has anyone brought this up to Toyota or the NHSA if applicable?

Yeah this is the first I'm hearing of anything like this on our 4runners, or the 3rd gens as well. How the hell can this be common? For something like this to be common you'd probably have to be driving a British or Italian car, certainly not a modern Toyota.

 

[zonianbrat]

I've heard of it a couple of times. Not only on Toyotas either. Known it ot happen to a friends Cherokee and another friends sisters pontiac G6. Every case the rear defrost was on. The G6 was asking for it as the rear window had like an inch of snow and she was hoping the defrost would melt it.....Yup.

I know my defroster wires are not connected to my back glass anymore. PO either had this happen to him or they shorted and popped off.

 

[chompster4runner]

$200 for new? Where? I see around 400+ for new. I need one for mine.

They don't deliver sorry.


Googling got me this
http://www.toyota-4runner.org/4th-gen-t4rs/73590-rear-windshield-shattered-morning-2.html

 

[Minn3sota]

This is not a common issue, but rather quite uncommon. They are however not related to any specific vehicle manufacturer or model.I suspect any rear opening door or hatchback is far more prone to this. I've had this happen to me on a family road trip many years back on a Chrysler product.

The root cause is likely unseen damage to the glass. Then during cold temperatures with the Defroster on you have expansion and contraction from the 2 varying temperatures. A defect in the glass such as deep scratches, gouges, chips will fail at some critical point when Expansion and Contraction are too much for the damaged point in the glass.

Why hatch-backs or rear doors more than others? Have you ever had a friend or wife/husband accidentally slam the rear door on your T4R? Do you remember that awful feeling you had when you heard the glass shaking like hell? It gets beat up in there. It's easy to damage the rear glass in these types of vehicles.

 

[chompster4runner]

This is not a common issue, but rather quite uncommon. They are however not related to any specific vehicle manufacturer or model.I suspect any rear opening door or hatchback is far more prone to this. I've had this happen to me on a family road trip many years back on a Chrysler product.

The root cause is likely unseen damage to the glass. Then during cold temperatures with the Defroster on you have expansion and contraction from the 2 varying temperatures. A defect in the glass such as deep scratches, gouges, chips will fail at some critical point when Expansion and Contraction are too much for the damaged point in the glass.

Why hatch-backs or rear doors more than others? Have you ever had a friend or wife/husband accidentally slam the rear door on your T4R? Do you remember that awful feeling you had when you heard the glass shaking like hell? It gets beat up in there. It's easy to damage the rear glass in these types of vehicles.

LoL, reading that just made me laugh. I don't know who it is in reference too. Like I said in the previous post. My wife smell something burning quite strong and freaked out. Turn off the defroster because she smell that before after using the defroster. Then pow! The glass blew.

 

[chompster4runner]

Just pulled the cover off to clean up the glass. This is what I saw so I guess I'll give Toyota a call tomorrow. Don't think much will happen because I am out of warranty.

 

[BlackWorksInc]

Yeah, that's what sees to be the issue usually is a hot spot formed by some sort of poor connection/corrosion on the contacts.

I might suspect a manufacturing defect since your picture doesn't show that much corrosion, but the instances are rather few and wide spread among the model years so I couldn't say for sure without examining the damaged parts individually for commonalities. You're the first picture I have seen of the actual burned part, but it all fits what caused the window to shatter.

 

[chompster4runner]

Yeah, that's what sees to be the issue usually is a hot spot formed by some sort of poor connection/corrosion on the contacts.

I might suspect a manufacturing defect since your picture doesn't show that much corrosion, but the instances are rather few and wide spread among the model years so I couldn't say for sure without examining the damaged parts individually for commonalities. You're the first picture I have seen of the actual burned part, but it all fits what caused the window to shatter.

Hey thanks for your response coming from a tech. The connection look nice and snug other than the burnt spot. I'll be picking up my new window later today and install it myself. I don't know what else to look for but taking it to a dealer is not the time that I have right now. And I'm out of warranty so I'm sure they won't cover the problem. :crybaby:

 

[gza526]

The same exact situation happened to my runner as well. What can I do to prevent it from happening again? I don't want to spend $250 replacing the back window every time I use the rear defroster.

 

[chompster4runner]

The same exact situation happened to my runner as well. What can I do to prevent it from happening again? I don't want to spend $250 replacing the back window every time I use the rear defroster.

I don't have a clue either. There has to be a timer and some sort of regulator to prevent it from overheating like that. If there was a short in the connection I would assume the fuse blowing out first before the glass. I haven't even touch the defroster after installing it. Which by the way is pretty easy. Maybe I'll look into the electrical diagram to see if there is a timer or regulator. Maybe Blackworksinc will chime in.

 

[BlackWorksInc]

I don't have a clue either. There has to be a timer and some sort of regulator to prevent it from overheating like that. If there was a short in the connection I would assume the fuse blowing out first before the glass. I haven't even touch the defroster after installing it. Which by the way is pretty easy. Maybe I'll look into the electrical diagram to see if there is a timer or regulator. Maybe Blackworksinc will chime in.

The issue is that it is designed with resistance built into it, the resistance may not be significantly high to cause a fuse to blow. But it is significant enough to concentrate too much heat at one point of the glass which is what is causing the shattering. The grid is designed so that the heat is spread out evenly in the glass, the rapid heating/cooling of just one spot causes it to shatter as evidenced by the burn mark.