Rear Window Shattered Twice – Possible Thermal Issue?

[Lightning64]

I’m wondering if anyone else with an F-150 Lightning has experienced their rear window shattering for no reason? I’ve now had to replace my rear window twice, and neither time was it struck by anything. Once in late October and now again in early February (colder months).

The first time it happened, I brushed it off, thinking maybe a small crack had formed from some unknown impact and later failed. But now that my replacement window randomly shattered last weekend while I was driving, I have a strong suspicion that this is a thermal issue.

I believe the problem might be related to the automatic preconditioning system. When the vehicle warms up on a cold morning before departure, it seems like the rear window defroster turns on automatically. Then, when I get into the cab and fully start the vehicle, the defroster turns off until I manually reactivate it if needed. This means the rear glass is potentially going through multiple rapid heating and cooling cycles every single morning, which could be causing stress fractures and eventual failure.

For reference, I have an F-150 Lightning Lariat with the power sliding rear window and rear defrost.

Has anyone else had their rear window unexpectedly shatter? I’d love to hear if others have run into this issue.

Can anyone see in the climate control programming if there is a temperature during remote start that the rear defroster automatically turns on as a convenience to try and defrost the rear window before you leave?

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[TaxmanHog]

Not seen this as a trend on the forum in the 2+ years monitoring issues.

I've frequently used remote climate start to sometimes very warm settings, no problems yet... knocking on wood.

 

[Heliian]

As a Canadian, my truck has done an insurmountable number of precons and defrost cycles and I hit the rear/mirror defrost manually quite a bit with no issues, third winter with it. It was - 25 deg C this morning at home and - 28 when I got to work.

Can't remember any reports of random rear glass breaking here either.

There could be a window frame issue with your particular truck that is causing it, make sure they inspect it closely after fully removing the window.

 

[jimfigler]

This is first I seen it reported.

 

[Grumpy2]

Have you seen the following??

https://www.f150forum.com/f118/another-rear-window-shattered-426302/


https://www.f150forum.com/f38/rear-window-defroster-issue-416927/

Apparently your choices are unplugging the heat near the window, or pulling the fuse.

 

[TaxmanHog]

Have you seen the following??

https://www.f150forum.com/f118/another-rear-window-shattered-426302/


https://www.f150forum.com/f38/rear-window-defroster-issue-416927/

Apparently your choices are unplugging the heat near the window, or pulling the fuse.

Is the rear window and defroster heat circuit the same as was the case in model year 2011, 2013, 2015, as our 2022-2025 F150's?

 

[GDN]

Haven't heard of it in the Lightning, but as quoted above this was a big thing for many years, years ago. This was 10 years ago - I had a 2014 it was for a few years around that time. There are other Ford forums with those threads and many many issues. It was speculated that it was the recipe for making the glass and seemed to be connected to the defroster.

 

[Scorpio3d]

I would suspect this is some type of manufacturing flaw in this particular vehicle?
Perhaps some type of imperfection in the sheet metal?
Did the original glass break in the same manner?

 

[TechnoSwiss]

I would suspect this is some type of manufacturing flaw in this particular vehicle?
Perhaps some type of imperfection in the sheet metal?
Did the original glass break in the same manner?

That was my first thought, had a windshield in my parents vehicle that kept cracking when the defrost was turned on, the shop finally figured out there was a lip in the metal frame the window was installed against and that was putting pressure on the glass and cracking it when it was cold and the warm air from the defroster hit it.

 

[tubby]

I’m wondering if anyone else with an F-150 Lightning has experienced their rear window shattering for no reason? I’ve now had to replace my rear window twice, and neither time was it struck by anything. Once in late October and now again in early February (colder months).

The first time it happened, I brushed it off, thinking maybe a small crack had formed from some unknown impact and later failed. But now that my replacement window randomly shattered last weekend while I was driving, I have a strong suspicion that this is a thermal issue.

I believe the problem might be related to the automatic preconditioning system. When the vehicle warms up on a cold morning before departure, it seems like the rear window defroster turns on automatically. Then, when I get into the cab and fully start the vehicle, the defroster turns off until I manually reactivate it if needed. This means the rear glass is potentially going through multiple rapid heating and cooling cycles every single morning, which could be causing stress fractures and eventual failure.

For reference, I have an F-150 Lightning Lariat with the power sliding rear window and rear defrost.

Has anyone else had their rear window unexpectedly shatter? I’d love to hear if others have run into this issue.

Can anyone see in the climate control programming if there is a temperature during remote start that the rear defroster automatically turns on as a convenience to try and defrost the rear window before you leave?

In the subject of your question on remote start and rear defrost, I have wondered the same thing and have even submitted a feature request to Ford for the app. When I remote start, it almost always turns on heat for the rear window and mirror. That is usually the first thing I turn off when I get in to start since I rarely need that. I have not heard of or found an option in the main screen to set this, but it would seem to be an obvious option. Along those lines but in the app, it would also seem obvious to have the heated wheel option to be on or off when you remote start. So in summary, the Ford Pass should really have the rear window and mirror and heated wheel be options when remote starting like the heated or cooled seats are. I apoligize if I maybe should have started a new thread on that.

 

[GDN]

Haven't heard of it in the Lightning, but as quoted above this was a big thing for many years, years ago. This was 10 years ago - I had a 2014 it was for a few years around that time. There are other Ford forums with those threads and many many issues. It was speculated that it was the recipe for making the glass and seemed to be connected to the defroster.

Here you go - 45 pages of discussion of back window problems in now "older" F150's. https://www.f150forum.com/f38/exploding-rear-window-145329/#post1555926

 

[TaxmanHog]

In the subject of your question on remote start and rear defrost, I have wondered the same thing and have even submitted a feature request to Ford for the app. When I remote start, it almost always turns on heat for the rear window and mirror. That is usually the first thing I turn off when I get in to start since I rarely need that. I have not heard of or found an option in the main screen to set this, but it would seem to be an obvious option. Along those lines but in the app, it would also seem obvious to have the heated wheel option to be on or off when you remote start. So in summary, the Ford Pass should really have the rear window and mirror and heated wheel be options when remote starting like the heated or cooled seats are. I apoligize if I maybe should have started a new thread on that.

Fordpass has a dynamic popup panel where you can select heated wheel on/off, usually that is remembered during my seasonal switch over. The same for the seats, you can select warm seat or cooled seat, it, likewise is remembered throughout the season, I generally make the transition in the fall & spring, during fickle days I may need to revert a change. You can only see this while a remote climate start is active, it's a set & forget situation most of the time.

 

[tubby]

Fordpass has a dynamic popup panel where you can select heated wheel on/off, usually that is remembered during my seasonal switch over. The same for the seats, you can select warm seat or cooled seat, it, likewise is remembered throughout the season, I generally make the transition in the fall & spring, during fickle days I may need to revert a change. You can only see this while a remote climate start is active, it's a set & forget situation most of the time.

I just looked for that and this is all I am seeing after clicking on Climate Settings. Front window defrost and seats. FP Version 5.12.0

 

[TaxmanHog]

I just looked for that and this is all I am seeing after clicking on Climate Settings. Front window defrost and seats. FP Version 5.12.0

Don't you have a heated steering wheel, or was it a truck that had it deleted in production?

 

[tubby]

It was added a few months after I took delivery, so yes, it was deleted in production since they were out of the parts needed for the heated steering wheel to function and wanted to get the Lightnings shipped out to customers.

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