1985 Ninety, wash/wipe switch issues

[old/new england]

Hi, new member here. Usually I find answers in a shop manual or an internet search, this problem hasn't yielded help in either way, so it was finally time to join a forum. This forum is the one I've most regularly seen good advice so...

It's a 1985 Ninety, 2.5 na diesel, I'm only the 2nd owner and it's really low in the mileage dept, so usually the fixes are straightforward, it's a bodge free Landy basically. My wash/wipe switch is a PRC3900 and for years it was annoying as it didn't want to cancel in the normal way; to stop the wipers I'd have to time the downward push of the wiper switch just as the wiper arm was approaching its rest position, otherwise the wipers would keep going. Finally I got tired of it, pulled the steering wheel and replaced the switch.

The old switch was almost certainly the original Lucas one. The replacement switch which I sourced, turned out to be a NOS Lucas one (the box was old looking, but switch looked new and perfect in its wax paper coccoon within the Lucas box). But it doesn't work properly either.

I've got a new version of the same problem; I can turn the wipers on, both low and high speed work fine, the wipers are not slow and laboured, they dart back and forwards happily, but once they're moving, they won't stop for anything. After five minutes of trying to push the switch to the off (down) position, I can eventually find the correct timing/angle/jiggle which works magically and stops the wipers, But clearly it's ridiculous. Oh, and if I give the switch just one nudge down, which should initiate just one wipe, that also commences endless wipers. Anybody have any insight? 

 

[western]

You need a new park switch on the wiper motor, it just clips on, a search for it on here will drag up the part number

[Puffernutter]

That what I was going to say, it's not the switch on the column, it's the one in the wiper motor causing the issues.

Peter

[old/new england]

I guess I had (wrongly) discounted that as an option as I've been able to force a 'stop' by jiggling the column mounted wiper switch. 

Thank you both, appreciate the replies. It looks like I'll be dismantling her to fit a 520160 then.

[western]

How to access & replace the park switch [this on a Td5, but similar process on older vehicles] 

 

[old/new england]

Oh that doesn't look too bad, mine is LHD with a simpler style dash but that link certainly helped me see what I'm searching for. Very useful.

Maybe it will be a simple job, we'll see. My other Landy, a one-ten V8 has a starter motor that's recently and intermittently begun failing, and in theory that's just simple too: battery disconnect, cables off, remove the two bolts and slide it out. But my arm can't reach it from above, and from below; between the chassis, steering and exhaust I can't get to it either. So it seems like simple is one thing, but straightforward is another, I'll need arm extenders for that job....

 

 

[western]

To get to starter bolts try a long or combination of extension bar on socket/ratchet handle

[old/new england]

Will do, I always manage it somehow.

Thanks for sharing your knowledge western, both now and the many times in the past I've read it here. All the best to old Kernow too, I used to live outside Launceston many years ago, the beauty down there takes some beating.

[western]

no problem sharing info, I see your truck is the same colour as mine 

we had snow last week, nearly brought kernow to a standstill. 

[old/new england]

I'm dragging this thread back to life because it's unresolved. Over the Summer I've been enjoying myself in my '89 ex-RAF V8 with the tilt rolled up, but before the bad weather sets back in -I decided to finally fix the wipers on my '85 hard top (the one with these wiper issues).

So I took the dash end off, and being a LHD it was easy to get to and I'd traded the park switch out in a few minutes. Suspected it couldn't be that easy though, and sadly I found the wipers still won't turn off. So in summary it's got a new steering mounted wiper stalk thing (genuine Lucas one), and a new park switch (blue box).

I considered the possibility the new park switch was a broken-from-new Britpart, and as I had a spare new wiper motor I took the park switch of that one and fitted it to the motor in my '85, just as a process of elimination. The wipers still won't stop, using park switch number 3 -so I plan to put aside the park switch as the cause.

I checked my earth was good, and it's completing the circuit fine. So I fitted the park switch back onto my spare new wiper motor in order to try out an entirely new wiper motor assembly. But instead of wasting more time fitting it, I just connected it whilst holding it my hand. Wipers still won't turn off.

So I'm just wondering if any of you have had this happen before?

 

 

[FridgeFreezer]

Do you have a meter to see what volts you're getting on which wires?

[old/new england]

I do, what are you thinking?

[FridgeFreezer]

37 minutes ago, old/new england said:

I do, what are you thinking?

It's controversial but I thought you might measure the voltages you're getting on the various wires, with & without motor &/or switch connected / parked etc. to see if it's doing something unexpected somewhere.

[old/new england]

I see what you mean, I've got nothing to lose at this point.

I'm trying to understand the flow of electricity; obviously when the steering column mounted switch is operated, voltage is allowed to pass down the line, where it goes through the park switch, and the wiper motor. I'm just struggling with the concept of it not stopping when I de-activate the column mounted switch.

While fitting the park switches, I noticed there was a ramp inside the wiper motor, positioned to operate the little plastic plunger which protrudes from the park switch. I'm assuming that is an on/off mechanism? If so, I'm baffled why 3 different park switches achieved nothing. I guess I'm still hung up on my new PRC3900 being a duff one.

[western]

the ramp tells the park switch to operate to switch the power on or off, Could be the ramp of the gear inside wiper motor is 180 degrees out, 

has your wiper motor been replaced with a non land rover item ? 

[western]

these threads might help 

 

 

[old/new england]

Non genuine motor? Not sure how to tell, there are no obviously visible markings on it. While working down there I noticed that somebody had spliced the black wire and crimped in a second earth wire, implying somebody has had a go at fixing this in the past. It's the only altered wire I've found on the whole vehicle, incredibly enough.

It's not a great comment on me that I've had it 5 years and never bothered to fix it (ashamed).

 

[old/new england]

Thanks for those two links, I'd found Gadget's one previously and found it very useful, so thanks Gadget if you happen to be reading.

While I had the steering column apart, I could see the scope for error there!!! In fact I was kind of hoping I wouldn't need to take it apart again for that reason...

The wiring diagram seems so simple, especially as mine (being an early 90) is a barely-Defender. I may just grab a genuine LR wiper motor and fit it, I always figure that it's never a total waste, as it's one less thing to worry about. The wiring diag doesn't show a lot more than those parts, the wires and the fuse. aaahhh.

[western]

My 110 is a 1989 so pre defender years, so was similar to yours before I modded it for intermittent front wipers using genuine parts. 

check the wires into the motor park switch agree with these photo's [taken from mine] the plug from the main loom will only fit one way.

[old/new england]

Yup, exactly the same there. Red at bottom, yellow in middle and then last colour at 90 degrees top.

The blue station wagon in my avatar is one from my past, but the white 90 just about visible behind it is the one with the wipers poltergeist.

My RAF V8 is an '89 though, I really like that year's simple '110' badge, personally. Even though most of them lost them ages ago. Little things for little minds.

[hurbie]

if you look below the parkswitch , there's the end of a shaft from the wipermotor, at the end of this shaft there needs to be a circlip holding the shaft tight to the back end ( and so the wiperswitch)  , i have had a recent motor where the clip was missing , this makes the shaft turn inwards and doesn't protrude enough to push the switch ...

 

[western]

2 hours ago, old/new england said:

Yup, exactly the same there. Red at bottom, yellow in middle and then last colour at 90 degrees top.

The blue station wagon in my avatar is one from my past, but the white 90 just about visible behind it is the one with the wipers poltergeist.

My RAF V8 is an '89 though, I really like that year's simple '110' badge, personally. Even though most of them lost them ages ago. Little things for little minds.

Mine still has the black & silver  Land Rover 110 badge on the front, I don't refer to it as a defender, it normally gets called 110 or truck. 

[old/new england]

1 hour ago, hurbie said:

if you look below the parkswitch , there's the end of a shaft from the wipermotor, at the end of this shaft there needs to be a circlip holding the shaft tight to the back end ( and so the wiperswitch)  , i have had a recent motor where the clip was missing , this makes the shaft turn inwards and doesn't protrude enough to push the switch ...

 

Ah, that sounds promising. I'll take a look when I have some repair time set aside again. I appreciate everyone's input. 

[FridgeFreezer]

19 hours ago, old/new england said:

I'm trying to understand the flow of electricity; obviously when the steering column mounted switch is operated, voltage is allowed to pass down the line, where it goes through the park switch, and the wiper motor. I'm just struggling with the concept of it not stopping when I de-activate the column mounted switch.

There's also ignition live into the wiper motor park switch which is fed back to the wiper switch on the GREEN/BROWN wire, when the switch is OFF it connects that wire to the slow speed wire to the motor, which causes it to run until the park switch flips from 12v (green wire) to GROUND, shorting the motor coils and stopping it dead in the parked position.

So, it's possible the park switch isn't quite doing its thing, or maybe if the ground connection is dodgy the park switch isn't getting the motor stopped and it's running past "park".

[old/new england]

Hi all, just a quick update on this, especially for anybody in the future who finds they've got the same issue.

So I bought a genuine Land Rover wiper motor, fitted it (which isn't a bad job) yesterday, but sadly things are still not operating right. Which means that in summary: I've replaced the column switch (genuine) 2 park switches (one Britpart, and an unknown removed from a spare motor I had lying around) and now finally a new genuine wiper motor -and I still can't turn off my wipers.

Frustrating, obviously, but I'll choose to find the silver lining which is that I now have new components throughout the windscreen wiper system, which should mean that once I've resolved this, I'll have another couple of decades before I have to do it again...

But more importantly is what I've learned, so; the park switch is a known problematic component on vehicles suffering from this, but the park switch is activated by the reverse side of the wiper gear (which is a separate part fitted inside the wiper motor) and I'm almost certain it's that which is causing my issues.

It seems that if the wiper motor has a black cylindrical casing then it's an aftermarket pattern part, and if the casing is silver then it's genuine Land Rover (based on all the photos I've seen of the genuine parts vs the aftermarket ones, and from what I just bought). When I took off my old one, it had a black casing, which means it's almost certainly pattern, which means that it has been replaced before. My new genuine motor one is silver, and came without wiper motor gear inside it, so I had to remove this gear from the malfunctioning wiper motor and transplant it into my new genuine one. So that wiper motor gear may now be inside its 3rd wiper motor. 

Whilst I'd got it all apart, I studied how the gear operates the park switch plunger, and considering it's the only part I havn't replaced, then for now I must assume it's the most likely cause of my issues. In my case, it's stamped with 115 degrees, but it seems there are 90 degree gears too. Any way I can only assume that it isn't moving the plunger far enough in, to activate the park switches 'off' function. While transplanting this part, I refitted the circlip mentioned above by hurbie, and I can see how that could also be a problem, although in my case it wasn't.

Any way, I am ordering a new wiper motor gear (only going with genuine at this point) and should be able to fit that part next weekend, and I feel obliged to take a few photos and share them on here, hopefully to help anybody else who is tearing their hair out with this in the future!