Hi!

When I bought my used focus it had a heated windscreen fitted but no switching inside for it (it's not the top model - they must've mistakenly ordered the heated screen to replace a broken one at some time). I'd like to make some use of it... would it be possible to wire it into the switch for the heated rear screen so it switches both?

Cheers!

Hey I would say no as the windscreen uses a higher power and has an auto cut out after 10 mins or so but hey I could and probably will be wrong

The front heated screen has its own fuse and relay as it uses so much juice :P

The headlights visibly dim when you turn it on, so if I were you I'd try to get it wired in as Standard as possible. If the wiring is there all you need would be the switch and relays. Also would need activating in the GEM module

have to agree the front screen from memory uses 3x the voltage of the rear wire those together and youll blow summat

think the cars with heated front screens have a bigger alternator too

If you turn on the ignition (but not start the engine) you can switch on the heated rear window but it won't allow you to turn on the heated front screen.

Must be to prevent you flattening your battery (as the engine & alternator aren't running) - which shows how much extra power the heated front screen uses.

have to agree the front screen from memory uses 3x the voltage of the rear wire those together and youll blow summat

Not being picky Arthur, but it's currant / Amperage not voltage, the voltage remains at 12 volts but the amperage drawn from the battery increases. :). I agree, you can't just put a switch in to turn the heated screen on.

Not being picky Arthur, but it's currant / Amperage not voltage, the voltage remains at 12 volts but the amperage drawn from the battery increases. :). I agree, you can't just put a switch in to turn the heated screen on.

Thought it was currEnt myself ? ;)

im not picky but its current a currant is a fruit mate lol :o

Calm down boys. Play nice now. :D

Now now ladies..

rear is 20 to 30 amps front is 2x40 so 80amps after digging around the screens go through the ecu to a central timer module if the car did not have a heated screen to start with you would have to wire the wires under the bonnet if you have them to the fusebox fitting the relay and 2x40amp fuses then wire the earthing points then swap the timer module from a car with heated front screens

heres some useful info. Mine is the climate pack so has the heated front windscreen. the alternator is 105amp. if yours is the same or more then getting power when the engine is on wont be a problem. your main problem would be regulating it to stay on for 10 mins as mentioned.

in theory, if you have the power and wires, you could install a timed switch to turn it off after 10 mins instead of programming the GEM/ECU/BSI