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Discussion Starter · #1 ·
I've had my car for nearly 6 years, and despite multiple software upgrades, factory rest, and recycling the setting. My rear defogger always turns off after 15 minutes, despite the setting set to continuous. does this work for anyone? I have a 2017 Impreza sport.
 

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My rear defogger always turns off after 15 minutes, despite the setting set to continuous.
I am curious... did you read something in the owners-manual which suggests the rear-defroster would be "continuous"?

I have NEVER owned a car with rear defroster which is "continuous". (since 1979) Such a setting may actually shatter the rear glass as the heaters can cause stresses within the glass.

Another question:
WHY would you need "continuous" rear defroster? Even when I have had 1/2 inch of ice on the rear glass... it is on long enough to loosen the ice so it falls off.

If you are dealing with 'fog' in the inside of the glass... that is an issue of moisture within the cab and there are other ways to handle that condition. (Removing the moisture which is causing continious 'fog' on inside glass)
 

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2019 Subaru Impreza Sport 5 Dr. Manual Shift
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I do remember in the settings on the center display a way of changing how long it stays on like the OP is stating. One of the setting was continuous. I've never set it there myself but I suppose there are places that are so cold or with a lot of people in the car breathing it might be needed.

I have no idea why if you set it it does not work though.
 

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2021 Subaru Impreza 5-Door Sport 5MT
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I've had my car for nearly 6 years, and despite multiple software upgrades, factory rest, and recycling the setting. My rear defogger always turns off after 15 minutes, despite the setting set to continuous. does this work for anyone? I have a 2017 Impreza sport.
This is a setting in your head unit. Another fun fact, side mirror and windshield defrost grids won't turn on unless its below 36 degrees F outside. To override this, hold down the defrost button until it flashes.
 

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One thing to consider; "continuous" is not the same as "always on". It does turn off with the ignition.

Having said that, I remember from when I worked at a Mercedes deal many years ago that MB had a unique rear window defroster, one where tiny little wires were in the glass between 2 layers (expensive replacement part, BTW...), and their rear window defogger was alone amongst every other manufacturer at the time in having a switch which could stay on continuously. Problem was, though, that there was such a small amount of current going through those little wires that it took a long time for them to melt ice on the glass.
 

· ModFather
2019 Subaru Impreza Sport 5 Dr. Manual Shift
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I've had Subarus forever and have never heard of that happening before or have had it happen to me. I think all of my Subaru's since 97 have had the wiper park heated section. I live where you really need to use it though. We get more ice storms than we do snow storms.
 

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2019 Subaru Impreza Sport 5 Dr. Manual Shift
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Ford had a system, I'm sure others do too, called InstaClear, where they had a thin sheet of clear metalized material sandwiched in with the laminate of the safety glass of the windshield. Basically it was a defroster you could see though that was over 100% of the windshield. Sounds like a good idea. I was in my roommate's Mercury Sable on a very cold morning when he turned it on. We heard a high pitched sound then the windshield shattered like a "Is it live or is it Memorex" commercial. That was a very expensive endeavor and fun morning...

Chevy had this too. I remember sitting in Z1 corvette and there was a cutout in the material in the windscreen the size of an Escort radar detector because radar would not go though that type of windshield.
 

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2021 Subaru Impreza 5-Door Sport 5MT
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I don't ever turn my on the defogger in my Impreza. I've read cases of the windshield wiper defogger causing the windshield to crack, and I don't want to risk that.
This is false. Now people letting their windshield wipers fall and smack the windshield will cause it to crack. If a windshield cracks, its because the glass was weak or other outside influences. Subaru uses double pane windshield glass and is perfectly compatible with running the defrost or else we wouldn't install it.
 

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Ford had a system, I'm sure others do too, called InstaClear, where they had a thin sheet of clear metalized material sandwiched in with the laminate of the safety glass of the windshield. Basically it was a defroster you could see though that was over 100% of the windshield. Sounds like a good idea. I was in my roommate's Mercury Sable on a very cold morning when he turned it on. We heard a high pitched sound then the windshield shattered like a "Is it live or is it Memorex" commercial. That was a very expensive endeavor and fun morning...

Chevy had this too. I remember sitting in Z1 corvette and there was a cutout in the material in the windscreen the size of an Escort radar detector because radar would not go though that type of windshield.
Yes, I remember those; the windscreen had a slightly rose-colored hue to it. You also could not use a radar detector, because the metal blocked radar signals waves. EZ-pass (which was new at the time) would not work from inside, so you needed to get an EZ pass transmitter that screwed into the front plate. Also, they were expensive to replace (almost always being replaced by a plain glass windshield), and seemed to have a shorter lifespan.
 

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Discussion Starter · #14 ·
This is a setting in your head unit. Another fun fact, side mirror and windshield defrost grids won't turn on unless its below 36 degrees F outside. To override this, hold down the defrost button until it flashes.
I know the first part of your statement. I did not know the bout the second part of the statement, I’ll have to try that out!
 

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2017 Limited Hatch
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Is it because the Sport trim comes with the basic climate control system and this might only work with the premium climate control system that comes in the Limited trim?
 

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2022 Sport 5-Door
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Is it because the Sport trim comes with the basic climate control system and this might only work with the premium climate control system that comes in the Limited trim?
I haven't tested the defrost override, but the Sport trim, at least for the hatchback, has the windshield defrost and heated mirrors. If you look at the defrost button in your climate controls, you'll see there's a heated mirror emblem next to the normal defrost symbol.
 

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2017 Subaru Impreza Sport
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I too have that issue. At first I would set it to continuous since that would be ideal, yet it would shut off at 15 minutes. So now I set it 15 minutes and just hit it again if the windows fog up again. It works pretty quickly since everything is already warmed up and not starting from a cold start. So it isn't much a nuance as one might think.
 

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2017 Subaru Impreza Sport
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Hey guys I took out the manual and read it for myself to find the answer to this continuous defroster topic. So according to the manual the continuous defroster is ONLY works if your Impreza is equipped with Auto Climate Control and has to be set up by the dealer to work. So the Sport model doesn't have continuous defroster even though there is a selection for it.
 
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