75ZT Community

On a saloon 2004 CDTi Connoisuer SE (facelift CDTi with under bonnet pump) 86k miles - the windscreen wipers have started going when parked. Yesterday at first it was intermittent but now today it was intermittent but now continuous. I quickly disconnected the earth on the battery without raising the bonnet too much.

It is the switch? Or should I swap the whole wiper unit by the plennium? Or is it water relays? Or relays?

I am searching the web and found incomplete threads in that it does not share the outcome and solution. The usual is wipers will not switch of when driving and they say:-
If the washer does not work (my washer also does not work) a thread says the wipers may think the washer is working and keeps trying to clear the windscreen
Another says of a wire rubbing by the passenger side front strut and try moving the wire.
And one says of a bad earth connection near the front passenger strut

I had wipers running front and rear, (its a tourer) was down to water in the spare wheel well. There is wiring in there, if you have hiline satnav.

Thanks Duncan. I don't have sat nav. But the feel of the car (that is new to me) is of previous owners not familiar with our TLC tricks and there will be leak in all sorts of places. I have just stripped the boot of carpets and sealed the side vents and rear lights. The board covering the spare wheel was very poor condition.

The only thing in this boot is the parking sensor module and DIY towbar wiring

I have been using a hose pipe to clean the rear arches and rear suspension arms where I have used Black Hammerite on the one side and doing more. I thought the wiring looms are the same on all models and so the wiring for sat nav would be near where I used a hose pipe around the rear arches and suspension arms? Also I was moving the rear bumper off to seal the rear side vents.

My battery is 11.7 volts from the wipers on when the car is parked so I have that off to charge with my 1990s charger.

look for water in the wiper motor connector just under the driver side plenum guard, unplug the wiper clean out with contact cleaner, and maybe put some grease over when you have plugged it back in, but Duncan is most likely on the right track.

Thanks Duncan and Steve, it fts with the last thing I did was to continually flush the rear wheel arches and suspension with a hose pipe trying to clean mud off to paint back Hammerite before waxoyl.

Satnav wiring is inside the car so not directly in the wheel arches. But the vents may have let water into the spare wheel area. Could also be water in the PDC connector.

Thanks Duncan, This evening I refitted a charged battery and relay and it has been fine. I leave a tissue on the wiper to know of movement when I am not there.

By 10pm there is slight condensation on the very top inside of the boot carpet exactly above the PDC. I now have a duster above the PDC to catch any water. I think that condensation high up in the wing has been a real long term issue for previous owners. Early yesterday I painted some black waxoyl high up inside the wing and need to put more to reduce condensation.

The other area I will try to improve is the o/s rear wheel arch wiring that goes under that narrow long metal shield and into a wide pipe under the rear seat and down. The big hole to the pipe at the front of the wheel arch is exposed and will allow road water in with the wiring - and my hose pipe wet it yesterday.

The front wipers (Saloon) still occasionally come on and stay on when they wish even though I have the boot very dry and the parking module and wires wrapped in dusters and towels so that I know all is dry.

There is a DIY towbar with 7 pin trailer socket that we tested as working fine with all lights of a trailer board (brake, side, indicators). But it has been fitted in a DIY style by a previous owner with blue tape and the clip connectors that people say are ok but without any relays in sight. I disconnected the earth lead of the towbar wiring but wipers still come on when they feel like.

I have a static de-humidifier pack in the boot, and also have one in the car on the rear shelf - in winter I have to change them every 1-2 months depending on how wet the weather has been. They are better than dusters and towels, since they trap the moisture rather than just allowing it to evaporate later. You can buy them here https://www.amazon.co.uk/dp/B015AOGP1S? ... humid&th=1

Thanks Kevin. I will try those.

In the engine bay I found some traces of water when I pull out the half dozen relays from the relay box (behind the n/s head light by battery). i will check that in the light.

I find the rear boot leaks on a saloon can on occasion be extreme, even towards half a litre a day. So I like towels and dusters (out of sight under/behind carpets/& high up) to catch suddenly appearing water while also telling me the direction it is coming from

I have found water/moisture in the relay box (in the engine bay behind the n/s headlight) and not only under the half a dozen relays (that are either green or yellow or black). but also to the next group in that relay box to the n/s there are "small" 40 amp and 50 amp fuses(?) Or are they relays relays?

I cleaned the moisture from under the green, yellow black relays but occasionally the wipers kept working when switched off and it was not until I got moisture out of those fuses did the wipers stop.

Good to hear you have hopefully found the cause of the problem and thanks for reporting back

At 2pm I cleaned the relay box with tissues to absorb obvious moisture that could be seen and used a vacuum cleaner on the contact holes for the relays (with relays out) and drove some errands for an hour and parked all fine. At 8pm I found the parked car in light rain with wipers going.

It felt there was an improvement in that I started the engine and could switch the wipers off but they started again after a couple of minutes.

I pulled the top green relay out to prevent wipers starting overnight and it was warm/hot when pulled out. I will look again in day light and when rain stops.

This morning wipers still work as they feel like when all is switched off.
- All of the saloon's rear boot and parking module feel dry (and is surrounded by dusters and towels and the ceiling of the boot is dry).
- The relay box looks still dry from my drying with a vacuum cleaner and tissues. I tried two different green 30 amp relays (that I had as spares).
- I used a spare windscreen wiper mechanism with motor resting on top and checking all is dry I plug in and that spare motor but it was working/running when all is switched off.

I haven't checked the interior fusebox by the glove box nor would I know what to look for. and it is awkwardly positioned so I cant see much

The obvious thing that is different about this car (04 CDTi saloon) is a past owner fitted a towbar with 'very DIY' wiring with one 7 pin trailer socket. The wiring has blue connecting clips on the two n/s light wires and a bulk of tape around all wires at the rear o/s lights but no relays to be seen. I had taken the towbar wiring earth off to try but wipers still come on as they wish.

I assume I will need to totally undo the towbar wiring and see if that makes a difference?
I imagine I could pull fuses out for lights and brake lights to test if that helps? Anyone know which fuses and their location?

Found something - Lots and lots of clean water in the rear drivers side passenger footwell and under the drivers seat (that fades at the front of the drivers seat). The very front end of the carpet by drivers pedals is dry. All passengers side appears dry. I have done a 'boot to cabin carpet leak' on the previous Rover 75 and that water gets to the cabin over time and is dirty and stinks. (Carpet out - and for a long time is the only solution for such dirty water). This is clean and more flooding the surface of the carpet in the rear drivers side passenger footwell. I did not have a sunroof on my previous Rover 75. I am suspecting this water is overnight heavy rain leaking from a sunroof drain? Maybe from the rear drivers side sunroof drain area? I bought to the sunroof drain kit from DMGRS and universal 1.5 metre brushes knowing I would have to clean these drains. I am wondering if it is clean water if I can pull up the carpet for just the footwell/under drivers seat/seat out and use a wet vacuum cleaner under the carpet on the affected area? Any comments and tips are appreciated.

ED I'm afraid to be the bearer of bad news but if you have a Sunroof then you will need to do the sunroof drain tubes, and only true way to do the job properly is carpet out, but you would need good weather for that, and it may take at least a weak to dry out.

In the mean time yes you a wet and dry vacuum to get the excess water out, but it will all be for nothing if you do not do the sunroof drain tubes i have an how to on here somewhere.

to see the photos you may have to down load Opera with it's built-in VPN to view them.

Thanks Steve. Today there is more heavy rain so thanks for the warning.

I am confused by what I am finding. I went to start with the rear drains in the saloon boot but I am puzzled the drain pipe connections look brand new and clean.

A Rover 75 owner had same problem here in 2013 and gave up trying to fix it

https://www.mg-rover.org/threads/water- ... lp.587690/

The driver side rear passenger carpet is already unhooked free from by the sill by a previous owner and I soon had a gallon of water in my wet vacuum cleaner. Water keeps reappearing from under the carpet.

I put my old style square Thule Universal roof bars with a 6' x 4' (1.8m x 1.5m) tarp wrapped around the bars to keep rain off the sunroof.

The weather is very bad and wet for a long time and I am wondering about sealing the roof becuase of the success with a tarpaulling on the roof rack the heaviest rain showers today has not refilled the o/s rear passenger footwell. May be by this sort of thing https://www.ebay.co.uk/itm/236674358823 ... R46OvcacZw

I now disconnect the battery because I leave the car unattended the dash warning was lighting up with various warnings on it's own with ignition off.