Front Wiper System - Fabia VRS

[nightkid]

Hi All

Appreciate your advices here.

My front wiper system (in all modes) stopped working yesterday. I've tried and noticed the following:

• Front washer and headlight washer works so assumed it's not the classic fuse issue; have checked the fuse 15 and 41 just incase which works fine.
• Disconnected the bonnet switch to see what happens; still no front wiper.
• I can hear the relay engaging everytime I try switching the wiper on so there's power going to the part of the system.  Not sure if the relay is in the body controller or as an external circuit.

 

Are there any other simple/obvious things I should check before getting the multimeter out on the motor/stalk connections? Are the fuses next to the battery part of that circuit? 

 

Thanks,

Edited 18 December, 2019 by nightkid

[Breezy_Pete]

16 minutes ago, nightkid said:

Not sure if the relay is in the body controller

 

Yes, it is. Body Controller is known as the Onboard Supply Control Unit, J517, in circuit diagrams.  A dual relay inside it does the wipers at each speed. The intermittent function is just done by timed energising/de-energising of (half of) this relay.

It's possible that the relay is behaving as commanded, but its contacts are worn out such that no current, or not enough current is passing them even though they are 'made' at the right times.

Battery box fuses won't be relevant. There is one (No. 2) for everything fed from the cabin fusebox but if that had blown you would have far more problems!

 

[nightkid]

@Wino thanks for the response. By any chance the ABS sensor is also regulated by the body controller? I had that warning light come up 3 days ago and assumed the hall effect sensors are out of its gap limit.  That happened before with all the corrosion on the wheel hub so assume it's the same issue. Won't have a chance to investigate that until the weekend.

Edited 18 December, 2019 by nightkid

[Breezy_Pete]

Nope. ABS has its own control module under the bonnet, just below the engine ECU. Check the strip fuses on top of the battery for that one.

[nightkid]

Great thanks.  Looks like I need to check the power and earth going to the motor to see if it's the motor or not.  I hope it's the motor as that's an easier/cheaper fix.  

[Breezy_Pete]

Yep, definitely rule out everything you can before blaming the relay, cos it's soldered to the circuit board and so not an easy-peasy fix.

 

[nightkid]

I assume the whole body controller will be replaced if the relay goes.  Are you implying the relay can be replace (with some difficulty) on the controller board?

[TMB]

1 hour ago, nightkid said:

  Are you implying the relay can be replace (with some difficulty) on the controller board?

 

It can be replaced, yes.

 

https://www.briskoda.net/forums/topic/473170-wiper-relay-replacement/

 

 

 

 

[Breezy_Pete]

Thanks Lee, I literally just sat down to answer this.

You can also replace the module but they're £hundreds new, and will generally need simple coding with VCDS to tell them what features their new home/car has if secondhand.

 

[TMB]

12 minutes ago, Wino said:

Thanks Lee, I literally just sat down to answer this.

 

 

 

[nightkid]

@Wino @TMB

Thanks for the advice. At least I have options without replacing the whole controller. Is the body controller the one located above the accelerator pedal? Haynes calls it the "electrical system control unit" according to their writing diagram.

It's not super clear how to get to it in the Haynes as it shows you how to remove all the facia panels in the car without breaking up the instructions. 

[Breezy_Pete]

Yep, that's the one. There are some guides in the Fabia Guides section that show how to remove the lower dash panel on the drivers side.  One such guide is about replacing the brake light switch, the other about the Evaporator Temperature sender.  There are useful picture sequences in both.

[nightkid]

Hope everyone had a good Xmas.

I've managed to take the wiper motor out and check the power going to it.  Accessing the bolts to remove the "engine compartment rear panel" was a pain as it required removing the ECU and part of the valve block.  

There's 4 wires/connections to the motor.  As a sanity check, could people give me their thoughts on the following:

 

Brown/Black - Earth

Green/Yellow - 12V full speed

White/Black - 12V immediate speed

Green/Black - ~2.2V (is this the switching volt?)

 

So at different stalk/wiper setting I see:

 

1) full speed

Brown/Black - Earth

Green/Yellow - 12V 

White/Black - 0V

Green/Black - 0V

 

2) Immediate speed

Brown/Black - Earth

Green/Yellow - 0V 

White/Black - 12V

Green/Black - ~2.2V

 

3) Variable speed - same as 2). I don't think my multi-meter is sensitive enough to see the volt modulating at the variable speed setting.

Brown/Black - Earth

Green/Yellow - 0V 

White/Black - 12V

Green/Black - ~2.2V

 

So it looks like power is getting to the motor and therefore I think the wiper motor is dead and need replacing.

[KenONeill]

18 minutes ago, nightkid said:

Hope everyone had a good Xmas.

I've managed to take the wiper motor out

Yes cheers.

 

Did you clean the spindles first?

[nightkid]

@KenONeill

You mean the spindle on the linkages? No, not yet. They seem to move freely when I removed the motor from it. 

[KenONeill]

17 minutes ago, nightkid said:

You mean the spindle on the linkages?

Yes; I ask because it's not uncommon that they're the actual cause of a wiper "failure".

[nightkid]

Anyone have any idea where to get a front wiper motor? Having spent this morning trying the only places found are either the dealer at £150 each or used on eBay at ~£20-30. The part number is 6Q2955119A. 

Are the LHD and RHD motor the same?

[Breezy_Pete]

Get the cheapest eBay or scrapyard one you can find just in case it isn't the problem. 

LHD part number for the motor has a 1 after the 6Q instead of a 2.

[nightkid]

Managed to ordered an eBay special but while waiting for it to arrive, the original motor started working. I suspect some water got into the connector and it dried out once I had everything apart. I did "carefully" jet wash it a week ago 😅😅

 

Bit of connector cleaner and reassembly everything. Managed to mess up the blade position on the first assembly; it's was 180° out of its supposed park position. That was easy enough to adjust and worth checking before replacing the plastic trim/screws.

 

I'm guessing that last pin is for the motor "park" position.

 

This did give me an excuse to clean all the rotting biomass from underneath the trim, replace the modified spray jets and reposition the wiper blade which was touching the paintwork. 

 

Thanks again @Wino @KenONeill for your advice. 

[Breezy_Pete]

Good news. Reminds me I need to do leaf clearance on both our cars. Moved recently to a lovely new home but now park under trees..

[nightkid]

Hi all

Annoyingly this problem has reoccurred but this time the variable speed isn't working but the other 2 speeds are.

I'll go through the obvious check again like last time this weekend with the multimeter and the spare motor I have but wondering @Wino if the relay switch in the interior module can cause this failure where just the variable speed isn't working? 

 

Many thanks,  

[Breezy_Pete]

Check that your bonnet is fully closed.