Anyone know where the heated windscreen relay is located on a 2017 Yeti L&K 1.4 TSi 4x4?

 

The heated windscreen was replaced by Autoglass last summer but is now not working. The switch lights up but Autoglass say no power at the screen connections. 

 

Fuse looks fine.

 

Skoda want £114 just to look at it, so thought I could at least check the relay...

 

I think the part number is 3B0 951 253 can anyone confirm?

Edited 20 January, 20215 yr by juan27

Relay carrier below the e-box, apparently, position 1.

36 minutes ago, Wino said:

Relay carrier below the e-box, apparently, position 1.

Sorry 'e-box'? Is that the fuse box in the engine compartment?

Yep

The relay I mentioned is about £27 from Hortons. Quite a price but after a Google of the part number seems can't be had massively cheaper.

So I've got round to having a look, anyone got any advice on how to access and change the heated windscreen relay? Looks as though taking the battery out might help but I don't want to disconnect that unless absolutely necessary. Can't see any obvious way to remove the "e box" for access.

12 minutes ago, juan27 said:

I don't want to disconnect that unless absolutely necessary.

You'll only lose the time and trip mileages, all fault lights on startup will go out within a hundred yards or so.

Maybe just try removing the battery retaining screw, then see if you can move it towards the engine enough to get access under the ebox.  I seem to remember the relay carrier may slide outwards, towards battery, but that may have been a different design.

 

13 minutes ago, Urrell said:

You'll only lose the time and trip mileages, all fault lights on startup will go out within a hundred yards or so.

 

OK I shall try the battery tomorrow. 

I think it may be like this: Skoda Workshop Manuals > Octavia Mk2 > Vehicle electrics > Electrical System > Wiring > Fuse holder and relay carrier > Removing and installing the E-box (relay and fuse carrier in the engine compartment) > Vehicles up to MY 05 (workshop-manuals.com) (first image).

Hi

 

I don't know what the power of the heated windscreen is, but I would imagine it's quite a lot, let's say 360 watts so it draws 30 Amps.  This means that all the connections in the wiring and between the wiring and the screen need to be in A1 condition.

 

I hope it is just a faulty relay and therefore a simple fix, but relays are usually fairly reliable things so prepare to be disappointed.

10 minutes ago, Wino said:

I think it may be like this: Skoda Workshop Manuals > Octavia Mk2 > Vehicle electrics > Electrical System > Wiring > Fuse holder and relay carrier > Removing and installing the E-box (relay and fuse carrier in the engine compartment) > Vehicles up to MY 05 (workshop-manuals.com) (first image).

 

Looks a bit different.

Get some pics as you go along tomorrow, may help others in future. 

15 hours ago, Austin 7 said:

Hi

 

I don't know what the power of the heated windscreen is, but I would imagine it's quite a lot, let's say 360 watts so it draws 30 Amps.  This means that all the connections in the wiring and between the wiring and the screen need to be in A1 condition.

 

I hope it is just a faulty relay and therefore a simple fix, but relays are usually fairly reliable things so prepare to be disappointed.

 

Screen is literally brand new. Appreciate relays are reliable, but to be honest I can't think what else the problem could be on a 2017 car unless someone has been messing about with it.

15 hours ago, Wino said:

Get some pics as you go along tomorrow, may help others in future. 

Ok will do

Edited 24 January, 20215 yr by juan27

Do you have a multimeter? You say the fuse looks fine, but measuring battery voltage on both sides of it would be more convincing.

Just now, Wino said:

Do you have a multimeter? You say the fuse looks fine, but measuring battery voltage on both sides of it would be more convincing.

 

Ok a fair point and I do have a multimeter.

Ok checked both sides of the fuse....

 I'll just check if there's another fuse for the relay coil.

 

Yep, fuse 8, 15 Amp one apparently. I think that one may cover a bunch of other stuff too though, so I think it would've affected other things if blown.

Edited 23 January, 20215 yr by Wino

2 hours ago, Wino said:

 

Yep, fuse 8, 15 Amp one apparently. 

 

No 8 in the e box?

Yep

So I took the battery out and replaced the relay. It is attached to a plastic rail that slides out, it's a bit tight to pass the battery tray but with jiggling you can do it. You'll need a T20 Torx to unscrew it.

 

We've had a couple of inches of snow today, now melting anyway so difficult to tell if it's done the trick. Ideally I'd like to put the meter across the screen terminals but I haven't worked out how to get to them yet.

 

Terminals on the "old" relay showed some signs of corrosion but probably not significant. I'll connect it up to 12v and see if I can get it to click.

That corrosion looks like the cause of the problem, in my opinion. Do what you can to clean up the female contacts and then exclude water from the area however you can.

I agree, that corrosion will have a serious effect on a circuit handling high current.  I suggest that even with a new relay you should try and thoroughly clean off any corrosion in the relay socket.  One way to do this is to spray with switch cleaner, then plug the relay in and out a few times.  That sort of corrosion shouldn't happen if the area is dry, so also look for any unwanted sources of moisture.

Difficult to see in my photos  but the relay connections are quite well shrouded. I did make an effort to clean the female side.

 

I wonder if the corrosion is just lack of use of the car in its past life. (bought at two years old and 10k miles)

 

Edited 24 January, 20215 yr by juan27

Ok I cleaned up the contacts on the original relay and tested it. 12V across the input and it clicks, but with + on one output terminal and multimeter back to negative on the other only getting 8.5V (consistently after checking leads and connections)

 

Doesn't seem quite right?

Edited 24 January, 20215 yr by juan27