spig212

The black wire is not coaxial as there was no screen braid. My thought is that drawings were updated but wiring looms hadn’t caught up for our cars. (Thinking the mk2 loom was common and used for early mk3)

That’s a great tip. Crimped up for now - if I get future failures the loom will get too bulky with crimps for the rubber shroud. So will have to go down the replace sections route. (Fingers are crossed for now)

@Breezy_Pete heading down a continuity check it goes to the demister. Got a 35Amp rated butt connector so going to repair with that.

Having brain freeze. The heater element is protected by a dedicated 30 amp fuse. Therefore, I will need a 30 Amp or higher crimp. Can’t help thinking this will be big. Am I missing something?

With only a 24 hour window before my daughter disappears with the Fabia I’ve done a heath robinson solder job on the plate lamps and repaired a brown wire that was on its way to breaking. see picture - each wire fix has a heat shrink sleeve and then I’ve resorted to an outer layer of insulation tape. For the black wire need to source a crimp - I think soldering will be a challenge with all that copper. I’ll have to wait a week before fixing this.

I did find in wiring diagrams a black wire going to the heater where the car variant includes a digital radio aerial integrated into the rear windscreen/heater. Can’t say by looking that is my setup.

@Yorkshiremidge @nta16 Do either of you know what the gauge of the black wire is? I’m guessing 2.5mm2 from using my wire strippers.

@Vanessa ive tracked down my fault. This post will be helpful to you https://www.briskoda.net/forums/topic/534290-rear-demister-and-both-licence-plate-lights-stopped-working/#comment-5961198

@nta16. At least I’ve not needed to resort to pins to track down and home in on the fault. Re your tip about glue. Would that work to support the two wires where the insulation has broken but wires in tact still? Or is recommendation to a preventative wire repair as @Yorkshiremidge is going to do. I recently repaired a desk fan - after stripping back the rotating mechanism needed a regrease. Works lovely but rejected by my daughter for a slight rattle. @both. Run out of light this evening but have stripped the wire insulation back. Just need to find some suitable wire and make the repair

Opened things up. Evidence of other wires under stress - blue/red and a brown. The black wire looks like two wires in a tiny bundle - is that the case?

I’m struggling to get the plastic grommet out. Flat blade screwdriver too fat. Any tips?

Some good news - at least progress. Found two broken wires. See photo. Yet to find the other ends or see if there are any other broken or fraying wires. One is black - earth or power? The other grey/red - which goes to the plate lamps.

Thanks for your tips too Yorkshiremidge especially with regard costs of looms. I had a similar warranty experience with a Ford Fiesta years ago where the all the dashboard lights would periodically and randomly go off in one go and randomly recover. Again, the dealer wouldn’t cover the fault cos it involved lights/bulbs. Didn’t matter that it clearly was a different fault since everything was failing. £700 later I had a safe car.

Thanks again for your tips. I work in the aerospace sector - no room for sloppy design - so I share your VW frustration. ”I’ll be back” once I have made some progress ….

Thank you ‘Nta16’. I’ll get on to this over the weekend, starting at the hinge. Are interior panels removable without special tools? E.g I understand from other topics the connector block ‘forward’ of the tailgate loom is behind left hand side boot panel.

This is my second posting about my rear demister on my Skoda Fabia Mk3. My rear demister hasn’t been working for some time and I’ve not been successful in identifying a broken wire. Now both licence plate lights are not illuminating. (Bulbs are okay and so are both fuses). Wiper and boot lock are okay. I suspect a further wiring fault in the tailgate. Any tips on how I should investigate if a broken wire is not obvious at the hinge between main body and tailgate? Thanks

Thanks PetrolDave. Please see diagram attached. The measurement is shown by the bold blue arrow. I've shown on the diagram how I imagined the circuit. See the relay within the J519 part of the diagram. I wondered if the HRW dashboard switch sends a ground signal to the BCM which uses this to energise the relay. I imagined that the electrical path for the power to the HRW would only be via the relay contact since its high current.

I've been able to do some measurements this weekend and confident the wiring from the BCM to the rear window heater is sound. I did remove the fuse and with the heater operating (relay clicked on), measure from the BCM side of the fuse connection to the heater 'wires'. The resistance through the circuit was high (100s Kohms). I was expecting near zero ohms i.e. a direct connection through the BCM relay. Without seeing a schematic of the BCM can't really discern what's going on from this. As the car is in daily use not going to remove the BCM to take a look inside. So, conceded it'll be a phone call to local Skoda garage and discuss the problem with them.

That I don’t know as yet. Is it a direct connection between the J519 BCM connector to the HRW ? Once I’ve done this measurement I’ll post an update. (Thanks for replies so far)

Yes, fuse 41 is okay.

Hello, I'm new to Briskoda. My 2016 Fabia Mk3 heated rear window has stopped working. I've deduced that the battery is okay, the dashboard switch works and I can hear the relay operate in the Body Control Module. I have inspected the heater 'wires' in the rear windscreen and all looks okay. Resistance check gave me a reasonable reading of a few ohms. However, voltage reading at the heater was 0V. Hoping that someone has some ideas of where I should go from here. I'm wondering if something else might have failed in the BCM or a problem with wiring between the BCM and heater itself, or loose connector. I've attached an image of the heated rear window circuit. Thanks.