As the title suggests, half the heated windscreen isn't working, specifically the passenger side. I noticed this last night as whilst it wasn't iced up, the car deemed it necessary to active the system. The inside of the screen was misted up with a bit of condensation and the heated windscreen quickly cleared the driver's side, but left the passenger side untouched. I turned the screen on with the button as well in case it was that but didn't do anything.

 

The system has been working because the other week it was a bit icy coming out of work at midnight the other week.

 

I've done an autoscan on VCDS and this has come up;

 

459017 - Heated Front Windshield 
          B1264 14 [008] - Open or Short to Ground
          Intermittent - Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 6
                    Fault Frequency: 1
                    Reset counter: 65
                    Mileage: 23677 km
                    Date: 2021.03.11
                    Time: 18:09:05

 

 

 

I've checked 2 fuses in the engines bay's fusebox, fuses 17 and 21, and confirmed both are working. These are labelled in the manual as 'ABS, ESC motor control unit, relay coil for the heated windscreen' and 'Windscreen heater - left' as both of those are normal fuses. Fuse 14 labelled Windscreen heater - right is one of those square ones and I don't know whether you can do a continuity check on those the same as a normal fuse.

 

On the passenger side on the black section at the bottom, there is a little stone chip, but that's been there for years.

 

Can anyone point me in the right direction to start checking things.

 

thanks

Have you checked the relay?

Years ago, Ford had an issue on the Mk2 Focus where opening and closing the bonnet would cause fatigue on the ribbon cable for the heated windscreen. The cable would eventually break causing this symptom. 
 

Mentioning as it may be something to check.  The cable loom on the Focus ran next to the bonnet hinge, hence the flexing and fatigue.

You've got an electrical break in the screen copper winding for the heated screen. 

 

Two options:

 

1) Pay for Skoda to check out the issue and electrically test the windings in the screen

2) Pay £380 for a new screen and get your car window repair specialists to replace it for you.

 

Thanks

 

 

Max

3 hours ago, Ecomatt said:

Have you checked the relay?

 

I've not no, because I'm not sure which one it is.

 

2 hours ago, varaderoguy said:

You've got an electrical break in the screen copper winding for the heated screen. 

 

Two options:

 

1) Pay for Skoda to check out the issue and electrically test the windings in the screen

2) Pay £380 for a new screen and get your car window repair specialists to replace it for you.

 

Thanks

 

 

Max

 

That sounds like the death knell for my windscreen then. I assume there's nothing else I'm able to do / check?

 

If the windscreen really is shot, then I'd probably do a claim through the insurance some way. 

On mine they are marked:

 

Windscreen heater – right

Windscreen heater – left

 

Fuse box in engine bay fuses 14 and 12 

 

I would probably replace both before going any further. You can check continuity on some square ones but most need pulling out and checking from the bottom

Edited 12 March, 20215 yr by flybynite

6 hours ago, flybynite said:

On mine they are marked:

 

Windscreen heater – right

Windscreen heater – left

 

Fuse box in engine bay fuses 14 and 12 

 

I would probably replace both before going any further. You can check continuity on some square ones but most need pulling out and checking from the bottom

 

so it's just they're just the same as a normal fuse, unplug them and do a loop test?

12 hours ago, tunedude said:

so it's just they're just the same as a normal fuse, unplug them and do a loop test?

 

Should be, just unplug and do a continuity test. Pulling them out and re-seating may even do the trick if they have got damp. How is the seal on the fuse box?

1 hour ago, flybynite said:

 

Should be, just unplug and do a continuity test. Pulling them out and re-seating may even do the trick if they have got damp. How is the seal on the fuse box?

 

I'll have a go at that. I need to see if I can borrow some needle point attachments as the croc clip ends aren't able to get in the gap.

 

Inside the fuse box appears ok, but when I removed both fuses 11 and 12, the terminals in the fuse box were a little green with corrosion. There is a line where the fuses have been on to. I wonder if just reseating them and trying to brush off some of the corrosion would work?

 

The main thing, however, which I want confirming is does the heated screen have a circuit for both the left and right hand side? Being protected by 2 fuses in the fuse box?

Edited 13 March, 20215 yr by tunedude

1 hour ago, tunedude said:

The main thing, however, which I want confirming is does the heated screen have a circuit for both the left and right hand side? Being protected by 2 fuses in the fuse box?

 

Yes that is, (and has always been), my understanding. The heated windscreen is split into two circuits with separate fuses so if one fuse has gone or become corroded you will lose half your screen.

 

Pull them out and a squirt of electrical cleaner is what I would do first, but get a new fuse for that side.

1 hour ago, flybynite said:

 

Yes that is, (and has always been), my understanding. The heated windscreen is split into two circuits with separate fuses so if one fuse has gone or become corroded you will lose half your screen.

 

Pull them out and a squirt of electrical cleaner is what I would do first, but get a new fuse for that side.

 

OK, I'll have a look at that. I don't want to start being too evasive with plugging stuff out. Half is working and I don't want to either break the other side or break another electrical item.

 

But I'll see what spraying a bit of cleaner does and then I'll clear the errors and rescan it. But I'll have to try and see if I can get the screen misted up. That's the real test.

I found this link when I searched on here, it actually on the Superb section but this page shows a wiring diagram for the heated screen. But I can't make head nor tail of it.

 

https://www.drive2.ru/l/530317274016383479/

 

I can understand there's 2 relays to make the screen work. I just can't decide where they are. I know one at least is in the engine fuse box, but I don't know whether one is in the cabin one.

 

I don't know if I'd tuned out from it, but when I press the button, I don't here a relay clicking into life. But I do for the rear screen.

@SashaGrace quick question regarding heat windscreens because I know you had your one replaced (can't find whether your car already had one or whether it was an addition) but do you know whether the connections for the positive side of the circuit to the left and right hand sides are accessible? Looking on pictures of the screen I'd assume they'd be under the scuttle plate.

 

Don't know whether that's the specific screen, but it's certainly a mk3 heated one.

 

I'm just thinking if they're there, I could disconnect the one connected for the passenger side and see if there's voltage when the screen is turned on. That'll be a way of determining whether it's the screen or the circuitry at fault.

Yeah they should be there. One on each side

Well, as simple as things could get, the plug from the passenger side had come out from the other plug which is clipped above the firewall.

 

 

I pulled up that side of the scuttle plate and could easily see the wire. Then as I traced it, it just come into my hand. It was just a case of plugging both back into one another. I'm a little worried now they've come apart in the first instance, but I tried to pull them apart without touching the retaining clip and it seemed firmly fitted.

 

I've not long come in from 'testing'. I threw a 2 litre bottle of water in the freezer earlier on and I got that chilled enough to be just on freezing. I poured that other the windscreen to get that cooled down. Whilst I was doing that, I threw the kettle on and then used the steam from that to fog up the inside of the windscreen. Then it was just a case of turning the engine and screen on and seeing things return to normal.

 

I can only assume it wasn't fully secured when it's come out of the factory and over time and driving, it's now come away enough to lose contact in the circuit. Just glad it was something as simple as that, as I'm not in the mood for having the car in the garage and or glazers whilst they charge me for it to be repaired.

1 hour ago, tunedude said:

Well, as simple as things could get, the plug from the passenger side had come out from the other plug which is clipped above the firewall.

 

Result!