Hi. 

On the first icy morning of this winter I've realised my new 61 plate Focus 1.6 Titanium has only the drivers heated mirror working but not the near side one. Also the front heated windscreen is not working, although the switch to it does light up, it doesn't defrost.

Are the mirrors and windscreen linked or separate issues? I also notice my rear heated screen takes ages to defrost, again could this be linked to the other problems?

Dave.

Just looked and the heated screen apparently has two fuses, left and right, but although I've not seen a fuse like it before they both look intact (see photo). Could there be a relay for the heated screen?

Also the fuse for the heated mirrors doesn't have a specified location in my book, it's supposed to be 47 and it's not listed in the book so I can't check it (see photos). Seeing as one is not working is there any other thing that I should look for to see what the problem is?

The mirrors are linked to the rear screen - seems a bit counterintuitive but they face the rear.  Mirrors are both on the same fuse so if one's faulty, it's likely to be the wiring or glass in that mirror.  You can pop the glass out quite easily and do a continuity check through the element.  You can also check for a 12v feed at the positive heater wire when the rear screen is switched on.

Rear screens always take forever to defrost, if all the bars are working, there's nothing much you can do about that.

The front screen does indeed have 2 fuses, so for both sides to be faulty it's probably not the fuse.  I take it you've checked it's fitted with a heated screen, not a cheap aftermarket replacement?  There is a relay for the screen, I can't remember which one off the top of my head but can check later if no-one else knows.

The main reason for the front screen to stop working is low battery charge.  Obviously you only need the screen heater after a cold start when the battery will naturally be at it's lowest so it's not ideal, but if you haven't used the car for a few days, it could just be low battery and no real fault.

Yes I can see the elements in the glass and the switch lights up, although that means nothing. I use the car every day so I don't think it would be battery. I assume there must also be a wiring connection to the screen itself somewhere, can that come loose?

If somebody knows which relay it is that would be helpful. 

Also when I push the button in the engine revs drop slightly and the headlights dim fractionally so I'm assuming that means power is getting to the relay at least if not the screen itself?

Also find the centre of the screen never clears properly on blower too, always leaves a few triangular misty bits near the rear view mirror. 

12 hours ago, fladavid said:

the centre of the screen never clears properly on blower too, always leaves a few triangular misty bits near the rear view mirror

That's likely caused by the plastic housing deflecting the airflow.

Since the engine speed changes and the headlights dim there must be power going through the actual screen elements. The relay wouldn't take nearly enough power to do that.

I'm not sure that little triangle of mist is a big enough blind spot to worry about!  

The relay should be R7, it's the large grey one towards the top right of your engine bay picture.  You can simply test it by touching the top while someone else presses the button - you should feel it click.  As Mike says though, if the lights are dimming and revs are dropping, it sounds like the power is going somewhere substantial!  

The screen is connected at the bottom of each end by a wire underneath the scuttle panel.  There is a chance they can rub on the bonnet hinges and snap or short out but it seems unlikely for both of them to go, and especially not to blow a fuse.

Oh Jesus hope that doesn't mean that the screen is at fault then?

Looking online somebody said that there is an earth strap for the screen on a Focus underneath the interior light for both items but didn't specify which Focus that was. My interior lights are further back, almost over my head, so I assume that's for an earlier Focus as it looks too far from the screen to be a point to earth it. 

That little triangle starts off as a big triangles right down to the bottom of the screen but bizzarly only over the drivers side of the screen, that photo is after a 6 mile drive to work with the blower pushing warm air up the whole journey.

Have you got a multimeter?  Really need to check if power is reaching the screen plugs for a starting point.  

This ad shows the connections pretty well.  The earth point is at the top as you suggest. (Picture 8 ) 😎

https://www.ebay.co.uk/itm/264746674881

1 hour ago, fladavid said:

That little triangle starts off as a big triangles right down to the bottom of the screen but bizzarly only over the drivers side of the screen, that photo is after a 6 mile drive to work with the blower pushing warm air up the whole journey.

Is the dual zone climate set to auto or is it different temps for each side?  Are you using the AC?  Heated screen is the quickest way to dry it but if that's not working, the AC should help.

I do have a multi-meter but the I'm not dead sure how to use one proficiently. Looks like the power leads would be under the wiper scuttle so that would have to be taken apart to check if they're intact?

No I have it set to auto and the triangles are there with air con on or off, it makes no difference. 

2 hours ago, fladavid said:

 

No I have it set to auto and the triangles are there with air con on or off, it makes no difference. 

Odd, A/C should definitely help in demisting, it absorbs the humidity and hence clears the moisture. Most people think of A/C just as a temperature control, which is incorrect, it also acts as a dehumidifier as well and if you say it makes no difference, I'm guessing it's not working either!

No it is working. Bought the car in summer and it is pretty cold. 

4 minutes ago, fladavid said:

No it is working.

With respect, if it's working, it will demist your windscreen...

On fully auto the vents might not be directed at the screen, but instead directed partly at feet or face which will reduce it's screen clearing efficiency.  Manually increasing fan speed may also help.

The multimeter test in this instance is pretty simple, you can't damage anything.  Just put the red probe into the screen heating plug from the car, and the black one on any piece of metal chassis or earth bolt if you can reach one.  Set to 'DC volts' and you should see around 12v when the heated screen button is pressed.  You will need to remove the wiper arms, plastic scuttle and metal scuttle for access first.  And you will need the engine running in order for the heated screen to work, it doesn't work on just ignition alone.

On the full climate control if you push the demist button it should set the vents to screen, fan and temperature to max and turn on both front and rear heated screens and the AC. On our Mk3 Titanium it clears a misty screen within a few seconds. If there's frost on the screen it takes a fair bit longer, obviously, but still starts to clear within 5 minutes or so I'd say.

On 11/21/2020 at 2:44 PM, fladavid said:

Yes I can see the elements in the glass and the switch lights up, although that means nothing. I use the car every day so I don't think it would be battery. I assume there must also be a wiring connection to the screen itself somewhere, can that come loose?

If somebody knows which relay it is that would be helpful. 

Have you got a fix for this as I’m having the same issue 

thanks 

On 11/24/2020 at 10:26 AM, TomsFocus said:

I'm not sure that little triangle of mist is a big enough blind spot to worry about!  

The relay should be R7, it's the large grey one towards the top right of your engine bay picture.  You can simply test it by touching the top while someone else presses the button - you should feel it click.  As Mike says though, if the lights are dimming and revs are dropping, it sounds like the power is going somewhere substantial!  

The screen is connected at the bottom of each end by a wire underneath the scuttle panel.  There is a chance they can rub on the bonnet hinges and snap or short out but it seems unlikely for both of them to go, and especially not to blow a fuse.

I’m having this problem, after checking in the fuse box, there was not an R7 there, if that’s where one is supposed to be, and there is no fuse 47 either, I have a Ford focus 2014, 1.6 diesel 

2 minutes ago, Tommi97 said:

I’m having this problem, after checking in the fuse box, there was not an R7 there, if that’s where one is supposed to be, and there is no fuse 47 either, I have a Ford focus 2014, 1.6 diesel 

Can we assume from your discovery, that the windscreen has never worked whilst you have owned the car, or, did it use to work, and now doesn't?

5 minutes ago, StephenFord said:

Can we assume from your discovery, that the windscreen has never worked whilst you have owned the car, or, did it use to work, and now doesn't?

Thanks for you’re reply, only the drivers side has worked properly and the passenger side doesn’t clear at all, it just leaves a line down the middle of the screen 

14 minutes ago, StephenFord said:

Can we assume from your discovery, that the windscreen has never worked whilst you have owned the car, or, did it use to work, and now doesn't?

I have also checked the owners manual and it’s saying R3 micro relay for front window defroster (partially heated windscreen)

2 hours ago, Tommi97 said:

I’m having this problem, after checking in the fuse box, there was not an R7 there, if that’s where one is supposed to be, and there is no fuse 47 either, I have a Ford focus 2014, 1.6 diesel 

F47 is for the heated mirrors. Windscreen fuses should be F14 & F16.

Windscreen relay on a facelift should be R3 as you suggested above.

This is quite an old thread with multiple faults and a different car so might be better to start a fresh one.

4 hours ago, Tommi97 said:

and the passenger side doesn’t clear at all, it just leaves a line down the middle of the screen 

So it clears a line down the middle of the screen on the passenger side ?

If that is the case, then it is the heating elements inside the screen which have failed and the only option is to replace the windscreen as they can not be repaired.