Wiper relay replacement

[Breezy_Pete]

I thought this was topical, given the weather...

 

Mk1 Fabia uses a circuitboard mounted relay to drive the wipers, which is great when it is working, but a little unfortunate when it wears out.  The circuit board in question is in the Onboard Supply Control Unit, physically located above the accelerator pedal in RHD cars, clutch pedal in LHD (I guess). It tends to be known as the BCM (Body Control Module) in later cars, and is not the same as the Central Convenience Module (which does locks and stuff).

 

The relay can be replaced, but must be unsoldered from the circuit board without damaging anything. I used hot air to do so, at work on my first try with a small, very expensive hot air gun.

Later, at home on another, with a much cheaper more domestic hot air gun like you'd get from B&Q for paintstripping etc.  Obviously, you need to get the local area of the board hot enough to melt the 10 solder joints, but not so hot as to catch fire or melt anything else too much.  Not trivial, but not too hard.

 

Here are pics of the location of the relay and one of it removed, the ten pin holes cleared out with a 'solder sucker' and/or 'solder wick', and the extracted relay to show part number etc.  I found these available on ebay from Poland I think, not too much <£5 each.

 

 

You're going to want to rule out all other possibilities first, like fuses, linkage issues, wiper motor etc. 

 

By the way, if you use the intermittent wiper setting, it wears this relay hugely faster than when on the constant setting.  Every time the wiper starts a back and forth sweep, and finishes it, this relay has to switch on and off. When on continuous mode, it just operates when you first switch on, and when you finally switch off.  Relays mainly wear out by the contacts getting pitted during opening/closing operations, rather than by hours spent in the energised state.

-do=add#.url -do=add#.url

 

I need to credit Briskoda member @anewman for supplying me with a known bad unit, in order to test my idea that relay replacement would fix it. He now has it back and may have it available for sale if anyone needs one...

 

Edited 14 October, 2019 by Wino

[anewman]

5 hours ago, Wino said:

By the way, if you use the intermittent wiper setting, it wears this relay hugely faster than when on the constant setting.  Every time the wiper starts a back and forth sweep, and finishes it, this relay has to switch on and off. When on continuous mode, it just operates when you first switch on, and when you finally switch off.  Relays mainly wear out by the contacts getting pitted during opening/closing operations, rather than by hours spent in the energised state

 

Ah that explains it then. I always opted for intermittent where possible, reasoning it was less likely to wear out the wiper motor.

[blackcat9493]

Thanks for this. Going to have a crack at it today. 

[Breezy_Pete]

It's come to my attention that if your control unit has a part number ending in F, as found in some or all early mk2 Fabias, a different relay will be fitted, unlike the one in my photos.

According to a couple of folk who have fixed their mk2s, expect to find an Omron G8NW-2U 12V DC fitted. 

[Rob_Grain]

I know this is an old Post but I just wanted to than Pete_Ex-Wino for the post regarding the Relay. My Brothers Fabia Mk1 Front Wiper motor stopped whilst working on the intermittent setting. I wasn't getting 12v at the motor even though I was getting around 9Volts. I checked the   fuses an they were both fine So I tried a new motor and this didn't work either. which was half a good thing because I then tested the original motor (Should have done this at the start) and there was life. 

I tested the motor with a Dewalt drill battery negative to the negative terminal on the motor and then the positive on the other terminals one by one to make sure that all of the speeds worked. and they did so now I knew I have a good motor and the wiring must be okay to give me some voltage.

I tested it with a good earth point to make sure that the earth was a good connection too just in case this was giving a lower voltage and all okay there.

 

I then found this post . I could here the relay clicking when using the switch Stalk so thought that would be most likely be all okay at least one of the intermittent or something would work so it came to the Possibility of the Relay in the Control Module under the Dash on the Drivers side.

 

My module is the same as the above images and Ibecause my brother had the car still I purchased a Relay the same as in the picture hoping that mine would be the same, After the relays trip from china I finally could try it yesterday and great news the Relay was the correct relay. just a head up the ++part of the Relay is the datestamp when it was made and so it will be different each time so the Tyco V23084-C2002-A403 With 10 pins was the correct one for me. 

 

TO De Solder the joints I had success with a solder sucker, I tried some solder wick but I couldn't get that to work very well, (I think it has been in the cupboard for too long) it took a while to get the solder removed and once most of the solder was removed I then started to puch the reylay through little by little to move the pins down and then the relay came out without any damage to the board.A cleanup of the joints and then a resolder of the new relay and test time.

 

straight away when I put the motor in to test worked like a charm. saving a lot of money but also the hassle of getting parts for this vehicle luckily the motor was working because I could only find left hand drive versions of the motor which wouldnt fit.

 

So thank you very much for people helping each other out on the forum and than you versy much to pete_Ex-Wino

 

 

As a quick disclaimer, this was my brothers daily drive and It could have gone badly wrong if the board was damaged during the relay swap, they aren't bad to do as long as you have some de-soldering practice first the pads are pretty big to work on without getting worried they will come off with the heat. but also it would be easy to damage the board and then it needs a new board so be careful if you do replace the relay and make sure you have the relay ready to swp to save downtime on the car. but it was well worth it

Thank you very much

[Breezy_Pete]

Well done. 

[StevesTruck]

I think I've got this issue. Front washers and wipers have stopped working altogether. But when you press the washers, the back wiper runs. Fuses are all ok. Does that sound like the relay? Any issues with swapping the whole board for a second hand one?

[Breezy_Pete]

12 minutes ago, StevesTruck said:

Front washers and wipers have stopped working altogether.

I don't think the relay would affect the washers?

 

Have you checked fuse 15?

 

See here: Wipers not working?? - Read this first!! - Skoda Fabia Mk I - BRISKODA

 

Looks like your issue, see PastyBoy's post in there, quarter of the way down page 1. 👍

 

 

Edited 16 December, 2022 by Breezy_Pete

[StevesTruck]

That was it, cheers, found the first 2 fuses, didn't think there'd be a third that didn't stop anything else working. 

[Skoda91]

Thank you I already fix it. It was the little fuse which was broken.

 

 

But now I had a new problem steering wheel angle sensor, no communication with code 00778, and wonder if it is fuse or relay?

 

With great regards

[Breezy_Pete]

1 hour ago, Skoda91 said:

I had a new problem steering wheel angle sensor, no communication with code 00778, and wonder if it is fuse or relay?

So you need to start a new thread in the general mk1 Fabia subforum Skoda Fabia Mk I (1999-2007) - BRISKODA, this thread is just about wiper relay replacement.

[Skoda91]

Okej thank you 

[jpadie]

does anyone know of a source of UK stock for the intermittent relay?  V23084 C2002 A403?  It's a DPDT micro-K non-latching format.  My usual suppliers of electronics components all have this as either obsolete or restricted

stock.

 

cheers

justin

[Breezy_Pete]

I have a couple (at least, haven't looked hard) with same part number except 303 at the end.

PM if you want to buy one.

[Graham Butcher]

@Breezy_Pete How are feeling today? I see you're still doing a sterling job of helping fellow members with their wee problems 👍

[Breezy_Pete]

Hi Graham, not three bad ta.  Feverish hot night, or first half of. Hoping that's my body seeing it off.

 

[Breezy_Pete]

Interesting one yesterday. A 6Q2937049F unit sent to me for relay replacement.

I didn't notice when taking this photograph, but here it is possible in hindsight to see the effect of damaged/cooked relay contacts just from visual (or tactile) inspection.

 

Zoom in on the relay just next to where it says Siemens VDO on the edge of the board. See a raised bump next to the O of Omron?

 

 

 

Was much easier to see the damage related to both sets of relay contacts once the relay was extracted:

 

New relays are smooth and flat across that top surface.

 

Edited 30 November, 2023 by Breezy_Pete

[J.R.]

Any idea what caused the overheating?

 

High resistance? Excessive current? Continuous and not intermittent use?

[Breezy_Pete]

The intermittent settings are the most demanding use case. As described in first post.

[jpadie]

are the G8NW-2 relays drop in replacement for the Tyco's?  
 

[Breezy_Pete]

Nope.

Tyco one fits suffix C and D units. 

G8NW for suffix F units as I see it.

Edited 10 January by Breezy_Pete
Extra info

[jpadie]

thanks for the info.  Swapped mine out with a combination of the kitchen oven (to preheat the board) and low melt solder to get the old relay out.  clean it up with wick and then use normal solder to mount the new one.   without my heat gun (my electronics lab is in a different country) I couldn't see a way of getting it done without low melt solder. 

[Aivar1988]

Just wanted to thank the OP! Changed the relay yesterday and this job is not for beginners. Use a soldering fan or bring it to a professional. It is very difficult to get the old relay out with only a normal soldering iron and it's easy to damage the two sided board. With the help of a desoldering pump I got only 4 legs out of 10 cleared. The rest I had to heat one by one and push the relay out until I was able to cut the legs between the board and the relay. TOOK ME HOURS!

Comfort module: SIEMENS 6Q1 937 049 D

Relay: TYCO V23084-C2002-A403

New alternative relay: HFKD012-2ZST

 

The old relay still worked, but it was short circuiting very rarely, making the fault diagnosing difficult. I opened the old relay and you can see the slightly burnt contacts (I bent it to take the picture).

 

I have owned the car for about 2 years now and this relay has been driving me crazy the whole time. I could hear something short circuiting and even dimming the instrument cluster for half a second and I couldn't figure out what was causing it, as it happened only a couple of times a year and the wipers kept working. Adding the not working power windows to this electronic mess (my next mission), it really didn't help me finding the source of the problem. I have even opened up the comfort module once before to check if there's any moisture damage, while trying to fix the power windows.

Finally I realized, that the short circuiting sound was occurring while the wipers were on the intermittent speed and working for a long time. I quess the contacts heated up or something. So after reading this post about the problematic wiper relay, my car has now one less problem.

[Breezy_Pete]

Well done. 

Interesting how it caused other problems!

 

Your electric windows are not really affected by any other modules. Driver's side and passenger side motors are data connected to each other, but nothing else. Unlike the earlier pre-facelift version which are CAN connected. Message me for more help. 

 

[Aivar1988]

48 minutes ago, Breezy_Pete said:

Well done. 

Interesting how it caused other problems!

 

Your electric windows are not really affected by any other modules. Driver's side and passenger side motors are data connected to each other, but nothing else. Unlike the earlier pre-facelift version which are CAN connected. Message me for more help. 

 

I really don't want to go offtopic here, but I was in the understanding, that every electronic "comfort" accessorie of the car, including the power windows, go through this module AND one time, the windows stopped working after another short circuit episode, with the instrument cluster dark for half a second. Looking back it was another rainy day and I had my wipers on. I will address the power window problem in the proper thread.