27 replies to this topic

[vince_13]

can anyone tell me why the heated front screen is on a timer? in comparison to the rear heated window where you turn it on and off, the front screen will go off after a length of time

[Lenny]

can anyone tell me why the heated front screen is on a timer? in comparison to the rear heated window where you turn it on and off, the front screen will go off after a length of time

The heated windscreen is more powerfull than the rear demister.
It is on a thermostat which trips off to prevent overheating
It also trips off to save your car battery and fuel consumption. Notice how your headlights dim when heated windscreen is active.
It draws 20amps of power from the car.

The heated windscreen is two elements fed seperatly through two fuses,
One element for passenger side and one for drivers side,
If a fuse ever blows you will clearly see the divide in elements as one side will be clear and othe frosty.

[martyntdci]

Ever since my alternator packed in and also had electrical gremlins at same time. I've not used the front screen. As lenny said it draws loads of power from every where and tbh imo it car.nt be good....

This is my opinion tho.
..

[k13r4n]

The heated windscreen is more powerfull than the rear demister.
It is on a thermostat which trips off to prevent overheating
It also trips off to save your car battery and fuel consumption. Notice how your headlights dim when heated windscreen is active.
It draws 20amps of power from the car.

The heated windscreen is two elements fed seperatly through two fuses,
One element for passenger side and one for drivers side,
If a fuse ever blows you will clearly see the divide in elements as one side will be clear and othe frosty.

+1 agree here lenny has it bang on also note
when your electrics are on your rear window will work whereas your front won't

[TDCiST]

Your rear should be on a timer also... I believe all focus have this now (please correct me if I'm wrong).

I think it's set to anywhere between 10 an 12 minutes and can be changed via IDS or that Russian software...

Whereas the front is timed at 4 minutes (I believe) but you rarely need more than this!

[Stoney871]

My rear demister switches off automatically.

[vince_13]

wow thanks guys, alot of info there i didnt know, yeh leeny i had noticed that, i always thought it was because i was on tick over, so dim the lights to divert the current to more necessary functions, no idea it was 20amps

i hadnt tried it with the engine off either but worth knowing

[Andy H Dibley]

wow thanks guys, alot of info there i didnt know, yeh leeny i had noticed that, i always thought it was because i was on tick over, so dim the lights to divert the current to more necessary functions, no idea it was 20amps

i hadnt tried it with the engine off either but worth knowing

Don't believe you can use either the front or the rear with the engine off.

If you think of them as effectively shorts across the the battery, that's what they are. The front is made up of a lot more 'elements' than the rear. If you look close enough they're spaced about 2mm apart and cover the entire screen. That's a lot of elements.

Top tip. If your car is snow covered, clean the door area, open up, start the car, turn on the heated screens (mine auto brings on the heated front and rear screens), then set about getting the snow off, leaving the windscreens till last. Then after a minute or two, then entire screen of snow will just slide off. The ice underneath will have melted and brushing away the covering of snow will leave you with a clear and clean screen to start driving.

[artscot79]

you cant switch the front on without the car running the car wont allow you to since it draws such a high current the car prevents it from being activated till the car is started even then if it detects a low battery it wont allow it to switch on great way to tell if youre batteries toast the rear is set to 15mins and switches off itself the front is as said 4 minutes trust me even with mega thick ice you dont even need 4 minutes and from experience just setting the aircon to hot and windscreen does just as good a job of melting the ice

[whitelightning]

Hi, can i join the "heated debate" ha see what i did there....anyway,

my front screen demists with a 2 inch line down the centre that remains un heated, like a focus splitscreen if you will?
Any ideas? No damage on screen stone chips etc. I looks to be the original screen too.

seems odd
thoughts.........

thanks

[artscot79]

the centre is the last part to heat up as it heats from the sides inwards if after 5 mins which is the max time the heater is on it still hasnt cleared then its likely the centre wires are broken though i doubt it the centre just takes a bit longer than the rest thats all

[whitelightning]

Thanks. hmmmm it doesnt get that long because it gets switched off.........lol!!! when i switch on again still wont clear, wires then?
Cheers

[artscot79]

Sounds like the wires if its just the centre thay doesnt clear but both sides do if you look close enough you may see the breaks in the wires unfortunately these cant be fixed the only other thing i can think of is the plugs under the scuttle need cleaned but that means exposing the pollen filter and i wouldnt do that till i needed to

[whitelightning]

Thanks, yeah that old pollen filter trim fight eh? Big jollies getting that out in one piece!

[vince_13]

heres a question, this morning on the motorway going along at 65 bout 2900rpm i put the heated front screen on and noticed the headlights dip, surely if the engine is running at 2900rpm therefore turning the alternator, surely there would be enough power being supplied for the lights to be on and the front screen on?