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RRPhil

Member Since: 22 Aug 2011
Location: Blackburn, Lancashire
Posts: 963

Blocking protection problem - front wipers

I’ve been having a problem with my front windscreen wipers just stopping for no apparent reason while they’re switched on (I don’t mean the ‘intermittent’ function – this is in both normal and fast ‘continuous’ modes).

Having read the workshop manual I know that the wiper mechanism has a ‘blocking protection’ function which cuts the power to the wipers if they’re switched on and there’s no wiper park signal received by the Body Control Unit for a period of 16 seconds (e.g. if the wipers are frozen to the windscreen or something physically obstructs them from moving). The BCU then only turns the power back on again after waiting 3 minutes or if the ignition is turned off & on again – and sure enough that’s exactly what mine do, although neither waiting for 3 minutes or keying off the ignition is much of an option at 70mph on the third lane of a motorway while passing a truck that’s throwing up huge quantities of spray.

Although I always believe that an ECU is the very last thing that should be blamed for a fault I thought I’d better first check that it wasn’t sat in a puddle of water or something due to a leak. I removed the passenger seat to inspect the BCU and its connections and everything looked absolutely fine.

Click image to enlarge

Body control unit lives under passenger seat

Click image to enlarge

BCU

I used my Faultmate to check for DTCs for the Body Control Unit and sure enough it had stored “Wiper motor blocked, park switch or wiper relay defective”. The wiper relay only costs £5 so I thought I’d try that first

Click image to enlarge

Wiper relay is mounted next to transfer box ECU behind the battery

but when I phoned to order one I was told by the Land Rover dealer that they’d never sold one before – the clear implication being that it was unlikely to be the relay at fault. I therefore decided to buy a new wiper motor/linkage assembly instead.

I’ve now fitted it and - guess what - the problem is still there

. I took the old motor apart to examine the park switch and there’s nothing obviously wrong with it

Click image to enlarge

Cam on motor drive gear which activates park switch

Click image to enlarge

Wiper park switch

I’ve therefore now ordered a wiper relay and am waiting for it to arrive. In the meantime I’ll have to keep my fingers crossed that this is going to fix the problem.

I just wondered if anyone else had had a similar experience with their front wipers?

Phil

Admin note: this post has had its images recovered from a money grabbing photo hosting site and reinstated

19th May 2012 10:44pm

47p2

Member Since: 05 Oct 2010
Location: Gone Beyond, Subaru
Posts: 8048

Just because LR have never sole one before doesn't mean they can be faultless.

20th May 2012 7:42am

Contraband

Member Since: 08 Nov 2010
Location: FIFE
Posts: 3697

Hope you get it fixed... But, what a great, detailed write up. Well done.. Previously..
Vogue SE TD6
Defender 90 2.4
Defender 110 TD5
Vogue 3.5 EFI

20th May 2012 8:40am

Cam-Tech-Craig

Member Since: 03 Aug 2011
Location: Gloucestershire
Posts: 16281

2015 Range Rover SVAutobiography SDV8 Loire Blue

Ive seen two with similar complaints... Both needed replacement BCU's...

Craig

20th May 2012 9:28am

RRPhil

Member Since: 22 Aug 2011
Location: Blackburn, Lancashire
Posts: 963

Okay, thanks. In that case I’ll try the new relay first, now it’s on order, but it sounds like I’m going to end up needing a new BCU. My BCU has been superseded twice by Land Rover since 2003 (from YWC000921 to YWC000922 and now to YWC000923) so I’m trying to find out from Blackbox Solutions if my Faultmate MSV-2 will allow me to get the new hardware & software versions to work on my vehicle.

Phil

21st May 2012 1:00pm

JonP

Member Since: 11 Jul 2011
Location: Surrey
Posts: 51

2003 Range Rover Vogue 4.4 V8 Epsom Green

Hi Phil
I had a similar problem with mine about 5 months ago same fault wipers would just stop
I replaced the wiper relay and to date not had a repeat failure hopefully yours will be the same
I did open the relay and found a small of loose metal floating about inside the case

Regards Jon

21st May 2012 1:40pm

RRPhil

Member Since: 22 Aug 2011
Location: Blackburn, Lancashire
Posts: 963

Thanks Jon - that sounds encouraging!

The new relay should arrive tomorrow, though unusually it's not looking like I'll get chance to test the wipers this week

Phil

21st May 2012 6:26pm

RRPhil

Member Since: 22 Aug 2011
Location: Blackburn, Lancashire
Posts: 963

Just a quick (& hopefully final) update. I’ve used my wipers for several hours now since fitting the new relay and not had any issues at all so I’m confident that, like JonP, this £6 part was the problem

Click image to enlarge

Just a shame that I’d spent £127, unnecessarily, on a new wiper assembly before getting to this point! – ho hum.

Phil

Admin note: this post has had its images recovered from a money grabbing photo hosting site and reinstated

9th Jun 2012 4:27pm

Joe90

Member Since: 29 Apr 2010
Location: Hampshire
Posts: 6407

Not like you Phil (says the man who bought a new transfer box motor that only proved he didn't need one!!) .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

Previous: L322 Range Rover TDV8 3.6 2008; L322 Range Rover TD6 3.0 2002; P38A Range Rover V8 1999

9th Jun 2012 6:42pm

thatgirl101

Member Since: 28 Feb 2014
Location: London
Posts: 45

2003 Range Rover Vogue 4.4 V8 Giverny Green

I've just come back from a trip to France in our L322 and experienced a similar problem - the wipers just stopped randomly and only turned back on when we restarted the ignition.

Do you happen to know the part number for the wiper relay?

21st Jul 2014 4:03pm

le25dse

Member Since: 15 Jan 2012
Location: Oslo
Posts: 78

ywb000060 ----------
2014 tdv6 (ex. 2004 td6, 1997 2.5 dse)

21st Jul 2014 6:43pm

thatgirl101

Member Since: 28 Feb 2014
Location: London
Posts: 45

Hi,

Does anyone have any tips on accessing the wiper relay? Can the battery just be moved forward (whilst still connected), or does it need to be removed completely?

Thanks

30th Aug 2014 3:25pm

Joe90

Member Since: 29 Apr 2010
Location: Hampshire
Posts: 6407

^^^^^

It has got to come out! .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

Previous: L322 Range Rover TDV8 3.6 2008; L322 Range Rover TD6 3.0 2002; P38A Range Rover V8 1999

30th Aug 2014 4:30pm

thatgirl101

Member Since: 28 Feb 2014
Location: London
Posts: 45

Thanks - all done. And like the poster above, the relay that I took out quite obviously had some loose parts in it. Hopefully that will fix the problem - I need a nice long rainy drive to test them out!

9th Nov 2014 6:27pm

mzplcg

Member Since: 26 May 2010
Location: Warwickshire. England. The Commonwealth.
Posts: 4029

2014 Range Rover Vogue SE SDV8 Corris Grey

^ Careful what you ask for unless you fancy gathering 2 of every animal on the planet.

9th Nov 2014 8:13pm

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