Hello everyone hope all is well, 

driving back on the motorway last night the front screen was getting foggy and I thought lovely i will switch on the heated front window and it literally did nothing, when I touched it with my finger i wasn’t getting warm at all but the light on the button went on and went out like it’s supposed to on the timer. 
 

The screen is in great condition with no chips of anything 

 

I only have 18 days left on warranty what do you guys think? 
 

regards 

 

Was this near the beginning of a journey? How’s your battery voltage?

1 hour ago, Discodevon said:

I only have 18 days left on warranty what do you guys think?

As stated, check your battery as if it's a bit low, it won't allow the high current use of your windscreen. If OK, drive straight to the warranty holder before they can weasel out of a repair!

Thanks guys this was on the motorway after about an hour of driving so hopefully the battery would have been alright? I’ll check it later, do I need to check with the car running or turned off? 

Check with it off. Having been sat for at least an hour ideally or you still have residual surface charge. 
 

If the car doesn’t feel the battery has enough charge it will still not let the high draw features work because it’s prioritising putting enough back in to the battery for your next start. 
 

When the battery is nearing the end of its life you can end up in a perpetual charging state where the car can never bring the battery up to a level it is happy to enable all features.

Have you noticed any other telltales of a low battery like system off to save power messages on Sync, keyless entry not working on some or all doors, interior lights not illuminating when you unlock the car, low quality parking sensor and warning tones, stop start never working, etc. 

This is Copyright of @unofix 😁

State Of Charge

Thanks guys I did see on another topic someone had written that It doesn’t come on unless below 7 degrees outside is this correct please? 

8 minutes ago, Discodevon said:

Thanks guys I did see on another topic someone had written that It doesn’t come on unless below 7 degrees outside is this correct please? 

I would be shocked at that, as there would be occasions where you'd need the demist function despite outside temperature. Did you get bored measuring the battery voltage? 🤣

Yes I was surprised at reading this as well because I’m sure it worked before in the summer when it was dewy but I never actually touched it to see if it was warm or not so can’t confirm, we have been using the car this morning so it’s not had any time for the battery to settle yet but there haven’t been any problems with the stop start it always cuts out and everything is working like the keyless entry etc 

 

Hello the battery seems to be good, I left the car for over 2 hours with the doors open because was hoovering it out the interior lights were on in the back and front and after I had finished it still says 12.4 on the battery meter which I thought was ok since the interior lights etc were on for over an hour? 

Edit now the car is locked and is settled it’s says 12.5 now 

I’d check fuses next then although it’s normally one fuse for each side of the screen so unlikely that both have failed. 
Im not sure what the max outside temp is for it not to come on. Is your outside temp reading working?

Thank you I will have a look tomorrow, will the fuses be easy to find? 

7 hours ago, Discodevon said:

someone had written that It doesn’t come on unless below 7 degrees outside is this correct please? 

I can certainly confirm that on the two Ford Galaxy's that I owned (twenty years ago), the heated front screens did not work if the outside temperature was above 7^oC

As for more recent Ford's I suspect that it is still the case but given modern technology and fully automatic climate control (includes front and rear heated screens) it is quite possible that the screens maybe turned on by pressing the "Max Demist" button.

Thank you very much! 
 

I will try and use the max demist function tomorrow and see if that works, if not should I guess I need to contact the garage I got it from? I read the manual and it doesn’t say anything like “above 7 degrees the front heated screen will not operate” 

Actually I can confirm that pressing the button in the picture you sent in red does indeed turn both screens power on the buttons, but the front doesn’t get hot 

8 minutes ago, Discodevon said:

but the front doesn’t get hot 

Silly question, but how do you know it doesn't get hot ?

You can't feel it with your hand.

33 minutes ago, unofix said:

it is quite possible that the screens maybe turned on by pressing the "Max Demist" button.

 

I think that turns everything on including diverting the Heat to the Windscreen and turning the Fan on to high speed.

There is a good chance that the modern Fords either do not turn on the Screen above 7c or hobble it with Pulse Width Modulation it if the outside temperature is quite high.

I know that the PTC Supplemental Heater in my car produces more heat and quicker the colder the outside temperature is. There are three separate Relay's for that though.

Personally I only use my Windscreen Heater to defrost the outside of the Windscreen when frozen and use the HVAC along with the Wipers if necessary to clear condensation.

Thank you i would have thought that you could feel the windscreen getting warm if you were to touch it? 

I know it was 9 degrees on the motorway last night so if it was a little colder it may have worked? 

7 minutes ago, Discodevon said:

Thank you i would have thought that you could feel the windscreen getting warm if you were to touch it?

If you could do that, get out of your car fast - it's on fire 🤣

15 minutes ago, Discodevon said:

Thank you i would have thought that you could feel the windscreen getting warm if you were to touch it? 

I know it was 9 degrees on the motorway last night so if it was a little colder it may have worked? 

I don't know for sure.

Was it the inside or outside of the Screen that gave you problems and what was your HVAC set to Temperature wise and Air con and where was the Air Flow directed to.

Sometimes when I come out of the Gym the part of the Windscreen nearest me and the Side Window mist up even in the summer if I've been working hard. I know there is a Humidity Sensor that works in Auto Mode but I override that and direct the Airflow to the Front Screen with the Air Con on and it clears almost instantly before the condensation has had a chance to register and much quicker than switching the Screen Heater on.

It also purges the air from the inside of the car quicker than it would normally.

I can confirm that if the battery State Of Charge (SOC) is low then one of the first things to be disabled is the heated screen. This is extremely annoying in the winter when the battery chemistry is cold and the heated screen refuses to operate. You can actually feel the screen getting warm when it is working. It doesn't get hot but you can feel that it is warmer than ambient. As standard the car will only charge the battery to 80% SOC, so I (and others) have changed the target to 95% with FORSCAN and consequently my heated screen now works all of the time. You could try leaving the vehicle attached to a smart battery charger overnight to see if the screen comes back to life, but if you do you must connect the negative charger lead to the negative chassis point, not directly to the battery or the Battery Monitoring System will get confused. You can connect the positive charger lead direct to the battery. 

Thank you do you know if the heated screen only come on below 7 degress, I checked the battery yesterday and it seems fine? 

So tonight I had the engine running with the lights on at idle, when I press the rear heated screen the headlights dim briefly and the engine note changes, pressing the front heated screen none of that happens 

2 minutes ago, Discodevon said:

... pressing the front heated screen none of that happens 

That suggests the front windscreen is drawing no current, should be about a 20a draw, so if it has no effect, doesn't appear to be working. That warranty still open? LOL