Heated Front Screen

[teammarkku]

hi dose anyone have any ideas why my new heated screen on my 03 focus comes on for 30 seconds then goes off and what the cure is cheers

[mintalkin]

it could be the timer relay in the fuse box playing up.

[teammarkku]

it could be the timer relay in the fuse box playing up.

cheers is it easy to identify which one it is ive only just got the car so no handbook yet

[GSE1986]

hi dose anyone have any ideas why my new heated screen on my 03 focus comes on for 30 seconds then goes off and what the cure is cheers

Mine does the same - i've assumed it stays on until it thinks it's clear and then turns off? In wintery weather it's stayed on for longer

[teammarkku]

Mine does the same - i've assumed it stays on until it thinks it's clear and then turns off? In wintery weather it's stayed on for longer

hi no mine goes off no matter the wether just when i needed it too, on our rally car its stright forward turn it on or off no fancy timers

[K2008]

Mine does this too. It says this in the manual though...

Mine does stay on for longer than 30 seconds, but often goes off before I need it to.

[hawker]

I've never actually timed it, but at a guess I would say mine turns itself off between 30-60 seconds.

The heated rear window stays on for much longer (probably around 5 minutes)

[teammarkku]

Mine does this too. It says this in the manual though...

Mine does stay on for longer than 30 seconds, but often goes off before I need it to.

cheers, i will just have to do it the old fashond way ,with a scraper.30 seconds is no good to anyone

[teammarkku]

I've never actually timed it, but at a guess I would say mine turns itself off between 30-60 seconds.

The heated rear window stays on for much longer (probably around 5 minutes)

cheers i guess its one of those things

[artscot79]

cheers i guess its one of those things

is it not a built in thing so that it doesnt heat the window up too hot too quick which can cause it to crack in the winter

[jeebowhite]

is it not a built in thing so that it doesnt heat the window up too hot too quick which can cause it to crack in the winter

Yes and No, because the Rear Windscreen tends to stay on for up to 5x the period the Front one stays on for, and from my experience, I know the front windscreen tends to get slightly more frost / ice on it, but no more than the rear. I may be wrong here, but is it not the fact that if the windscreen keeps heating up and gets too hot, it becomes more fragile, and in an accident, does it not reduce its strength? I think the reason it comes on and goes off after about 60 seconds (on my model) is because it heats the windscreen, removes the condensation / fog on the inside, and/or helps to de-ice the front, and then stops to let it cool back down to a decent temperature.

I know it doesnt heat up to like 300 degrees centigrade, but from my Science Lessons all those years ago, I think its all to do with the structure of glass particles and temperature etc etc yada yada yada...

Feel free to tell me im wrong though!

[fredsknekt]

HI.

Mine front mirror heater stays on for several minutes even If It's cold or not.

Yesterday we had 24 minus degrese and It worked as it should, I would not be suprised if It's youre Time reley for the front mirror heater false.

Sorry my english are not the best.

[mjt]

Yes and No, because the Rear Windscreen tends to stay on for up to 5x the period the Front one stays on for, and from my experience, I know the front windscreen tends to get slightly more frost / ice on it, but no more than the rear. I may be wrong here, but is it not the fact that if the windscreen keeps heating up and gets too hot, it becomes more fragile, and in an accident, does it not reduce its strength? I think the reason it comes on and goes off after about 60 seconds (on my model) is because it heats the windscreen, removes the condensation / fog on the inside, and/or helps to de-ice the front, and then stops to let it cool back down to a decent temperature.

I know it doesnt heat up to like 300 degrees centigrade, but from my Science Lessons all those years ago, I think its all to do with the structure of glass particles and temperature etc etc yada yada yada...

Another thing that may be pertinent is that the front screen is laminated and the heater wires are buried in the structure whereas the rear screen is a single piece of toughened glass with the heater printed on the inside surface. Also the front screen is susceptible to stone chips from which a crack can propagate so with the buried heater producing localised heat stress in the glass it's more likely to crack. A few years ago my daughter had three front screens crack in her Fiesta in quick succession when she used them in frosty conditions.