Front and Rear Window Demister/Heater not working

[DarrenAY07]

Hello All,

My father has a 2013 Fiesta Titanium it has the climate control, but he's having an issue in that if you press the Heated Screen or Rear Window Demister buttons the light doesn't come on and the windows don't demist/heat etc.

I've had a look at the fuses in the engine bay and behind the glove box but all seem ok, would this suggest a problem with the relay or am I missing something else? The aircon system seems to function ok.

 

Thanks for any help

[alexp999]

I assume the engine is running when you are testing them?

(I know it sounds obvious but lets get it out of the way :) )

[DarrenAY07]

Yes, even with the engine running the LEDs dont light up on the heating controls

[alexp999]

I don't know if there is any battery protection on the Fiesta which might prevent them coming on.

Do you hear any relays when you try to turn them on?

When was the car first registered, you might still be in warranty to have a dealer look at it for nothing.

[DarrenAY07]

It's had a lengthy run today but still not lighting up.

 

No clicks or anything when the button is pressed, it was registered Jan 2013

[Zico]

Hi Darren.

I've the same issue in my works Fiesta Van that I only noticed last week when trying to clear some mist on the rear screen.

Have you found out the cause?

[Heydude]

Darren, did you ever get to the route of this problem as I am experiencing the exact same issue with my 2013 Titanium. Going in to the garage on the 24th Sept, be handy if you had any info I could pass on maybe.

Thanks in advance.

[walkas]

Hi,

I have the same issue with my 2013 Fiesta!

[Sharny]

Hi, I have the same issue with my 2013 titanium. Took it to ford dealer who cannot find an exact cause and have said they think it’s likely the computer needs replacing £450, but they cannot guarantee this will fix the issue. Anyone else had the issue resolved? Or been told the replace the computer.”?

[Bobby.a]

Hi all have a 2013 titanium with same problem of both front and rear screen heaters not working this happened last year for a while then started to work again and now they have stopped again any solutions anyone.

 

[peter.nixon]

I have the same problem but no one seems to know the answer 

[unofix]

4 hours ago, peter.nixon said:

I have the same problem but no one seems to know the answer 

Lots of people on here know the answer.

Charge your car battery overnight. Make sure the negative lead of the charger is connected to the vehicle chassis earth point and not the battery.

Then reset the BMS (battery monitor system)

Wait for it to be cold outside (below 7C) start your engine and switch on your heated screens.

[The Elite Collection]

I’ve reset the BMS and both front and rear heated screen buttons illuminate👍🏻

Easy to do with out diagnostic equipment.

turn ignition on, press rear fog light switch 5 times, press hazard switch 3 times, the battery light should flash 3 times start car and try the buttons. Worked for me

[Jv24]

On 11/23/2022 at 9:54 AM, The Elite Collection said:

I’ve reset the BMS and both front and rear heated screen buttons illuminate👍🏻

Easy to do with out diagnostic equipment.

turn ignition on, press rear fog light switch 5 times, press hazard switch 3 times, the battery light should flash 3 times start car and try the buttons. Worked for me

Just tried this and it worked for me. Thank you 👍 

[unofix]

5 hours ago, Jv24 said:

Just tried this and it worked for me.

Oh dear !!

Resetting the BMS with out replacing the battery was not a good idea. You have now reset the 'Days in Service' counter so know one will now be able to tell the age of the battery. You have also reset the State Of Charge (SOC) which is why, for the moment, the screens are working. The SOC of the battery was in fact low and was requiring a charge. Now you can potentially expect some extra problems as well as the screens not working again.