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Rear Wiper W639

45224 Views 34 Replies 9 Participants Last post by  Jamesbil
Hi Folks,

I am after some advice. The rear wiper on my 109CDI tail gate has stopped working and I am hoping someone will be able to advise me on how to test the wiper motor.

It has a 3 wire plug going into the motor. One of the wires has 12v going to it at all times with the ignition on.

Many thanks in advance

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You will find that is down to the canbus showing a door open.
Same thing as when reverse is selected and the wipers are on the rear wipes and the washer squibs.
All from the front sam unit control.

With your new motor you can also fit the later wiper arm and blade same fitted to new models.
With your new motor you can also fit the later wiper arm and blade same fitted to new models.
Thanks for the info, I don't suppose you have a photo of this later wiper arm and blade?
you learn something new every day.............

its what makes it worth carrying on!


Thanks for the info, I don't suppose you have a photo of this later wiper arm and blade?
Sorry I don't have a picture.
It is the same type fitted to the front.
Go to MB parts and ask for the latest arm and wiper blade.
Have a look at a 2011-2012 Vito and you will see what I mean.
Hello Malcom, Regarding Rear Wiper Motor not working with tailgate up... reading the Vito owners manual (page 45) its says "i-if the vehicle is stationary and you open the tailgate/rear door*, the rear window wiper will stop...and resume when closed or vehicle starts to move"... from my experience that is around 10kmh.

I tell you this after a "B" service 2 days ago, now my rear wiper wont stop! Doh, trying to find the relay? any ideas? I have removed the fuse F7 as you correctly identified to stop it while driving, but think the relay is jammed on, i think there is one in the wiper but being 639 think there has to be another in the front somewhere???
OK, after much gnashing of teeth i have found (as identified on this website) that the rear wiper motor was full of water, and had been for some time. if i knew how i would post an image of said water damage, anyway pulled apart, degreased, regreased, filed down smooth the brass contact plate, re-soldered some connections & re-assembled = all working. Cause of damage and reason for fault straight after MB Service - they test the wiper/washer systems and filled the motor with water!... as a consequence of the wiper water passing through the motor shaft onto the wiper arm - the chrome plating on the wiper drive shaft has degraded and now leaks wiper water inside the motor. So i have disconnected the rear washer motor at front water tank and water pipe connection inside tailgate....Next job, replace rear shocks, Quoted $924 + 143 labour by MB service agent, think i might go ebay shopping...Love to Drive my Vito :) Sparky Graeme
if you feel like taking it off the door again, a small (say 4mm) hole in the bottom of the casing will prevent the water building up again.

normal cause is a worn or damaged sealing ring on the water pipe.

the hole is not in the case for the simple reason that if it was, then water could drip down the inside of the door and rot it out along the bottom seam... a replacement motor is the cheaper option.

if you get a small piece of alloy or brass tube, from a model shop, and drill the hole in the case so that its a pushfit (in this case 3mm brass would be ideal) into the hole.
trim the pipe to about 20mm and use a modern epoxy repair strip (the type that has 2 strips you knead together or a "stick of rock" with inner and outer layer) knead well and stick around the pipe/case joint.
then put a length of pvc/silicon tubing (model shop) onto the tube and lead it out through the door bottom or panel.

a lot of instruction, much less actual work and it solves the problem for a couple of quid
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Yep, thanks for your thoughts, I did drill 2x 2mm holes about in the bottom of the case where the water/condensation had been resting and caused the corrosion, I thought about a permanent drain, but thought i might repair the faulty shaft instead, but then i thought (yeah i know ...a lot of thinking :)) maybe easier just to clean the rear window when i'm at the servo next time :)
Hi, I have similar issues. Rear wiper or heater dont work on a 2012 639 viano. Motor replaced with a tested and working one but in the van it wont work. Rear washer doesnt work. Rear heater doesnt work and when you press the heater button it just flashes orange for a few seconds. I have also fitted a new rear tailgate lock / catch incase it was the catch switch but still nothing. Any ideas? perhaps someone has a wiring diagram or layout drawing of my fuse box so i can check relays?

Thanks in advance.
Hi Ryan, I havent had that many problems with my rear door. only the wiper pump problem listed previously and had to replace the catch (mine is the full overhead door).
Im not familiar with the wiring harness but Id suggest if every component on your door is not working the only common denominator would be the wiring system and in particular the earth wire.

I do know that the wiring harness wires are a little in-flexible, meaning they do fail where flexing a lot - eg. my LH door speakers work when the door is open or taking a right hand turn :) but never followed it further, but have read similar circumstances on this forum.

If you PM me i have the full wiring diagram for the W639 - probably got it from this forum somewhere...

Thanks vito sparky but I cant send pm's yet as my post count isnt high enough. Can you pm me?
This is an old thread but let me share my experience. I have Viano W639. My rear wiper was stucking and after that it was also leaking water bottom of my rear door and stop working. I took out the wiper motor opened it and it was rusty with water in it. It is a defective design I think because water gets through the center of wiper pivot. Any leak may occur due to occlusion or something that cause reaching water into wiper motor.
Toy Wood Motor vehicle Gas Machine
Automotive tire Bicycle part Automotive lighting Wood Wheel

Behind the green wheel there is a metal plate for parking wiper to its original position, motor and wheel rotates one direction only and arm mechanism makes the bi-directional movement. The metal plate was also worn out on one side, may be due to electrical damage. I reversed the plate and cleaned the rust. But this time wiper was always on just after turning on the vehicle.

Clock Auto part Font Watch Circle
Wood Bicycle part Hardwood Automotive tire Auto part

So I realized that there is also an electrical problem. There is a relay at the back of the device with a plastic cover on it but you need to desolder to get it out, I figured out that the plastic material was melted and the relay is not functioning properly.

Hand Camera accessory Finger Cameras & optics Film camera
Wood Gesture Thumb Finger Nail

It was stucked to one side with melting plastic (heat by electrical de-charge maybe) I cleaned and fixed the relay and it just works fine.
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Just few weeks ago I fixed the rear wiper motor on my 113 W638. Same issue as yours, the leak comes from the washer water pass-through seal at the centre of the spindle and allows water to collect in the bottom of the enclosure. In my case the motor drive shaft rust-seized in the bronze bush and I was lucky I could split the whole thing. To reassemble it I replaced rivets with bolts to keep it together). Because the washer water feed is not as important to me I just disconnected it as I don't want it to seize again.
Rubbish design.
Front wipers watering system is much better and I may run the feed in the same way. To have it designed this way is worse than a built-in obsolescence iPhone style.
I need to look at mine tomorrow, any advice on removing all the plastic inner trim without breaking it?
so my wiper is running all the time, is that a motor fault or switch fault?
also, has anyone tried this repair kit?
repair kit
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